TW202012771A - Internal combustion engine and control system - Google Patents

Abstract

The exhaust gas discharged from the combustion chamber 20 flows through the exhaust flow passage 42 of the internal combustion engine 1. The reducing agent supply unit supplies the reducing agent to the exhaust flow passage 42 via the nozzle 61 attached to the exhaust flow passage 42 and mixes it with the exhaust gas. The reactor 66 brings the exhaust flowing in from the exhaust flow passage 42 into contact with the catalyst to carry out the NOx removal treatment. The exhaust gas that has passed through the reactor 66 is led to the flue 81. The bypass passage 681 bypasses the reactor 66 and connects the exhaust passage 42 and the flue 81. The bypass valve 682 opens and closes the bypass passage 681. When the valve opening process of the bypass valve 682 is detected, the supply control unit controls the reducing agent supply unit to stop the supply of the reducing agent to the exhaust flow path 42. Thereby, the inflow of the reducing agent to a part downstream of the reactor 66 can be suppressed. A control system is also provided.

Description

Internal combustion engine and control system

The invention relates to an internal combustion engine and a control system.

In the past, in order to reduce nitrogen oxides (ie, NO _x ) contained in the exhaust gas of marine diesel engines, SCR (Selective catalytic reduction) denitration devices were installed on ships. For example, in the exhaust gas denitration device of Japanese Patent Laid-Open No. 9-150038 (Document 1), urea water is mixed into the exhaust gas as a reducing agent and sent to the exhaust gas denitration device, whereby Nitrogen oxides are reduced and converted into harmless substances such as nitrogen and water.

In addition, Japanese Patent Laid-Open No. 2017-186999 (Document 2) proposes a technique for updating a high-pressure SCR system in a marine engine system. In the marine engine system shown in FIG. 4, the exhaust gas delivered from the combustion chamber to the exhaust gas receiver (receiver) is guided to the turbo of the supercharger via the high-pressure SCR system. In the high-pressure SCR system, first, urea water or the like is supplied as a reducing agent to the exhaust gas fed from the exhaust gas collector to the gasification/mixer through the reactor/sealing valve. In the gasification/mixer, the reducing agent is vaporized and decomposed into ammonia, mixed with the exhaust gas, and then led to the SCR reactor. In the SCR reactor, nitrogen oxides in the exhaust gas are reduced and converted into nitrogen, water, and the like. In the marine engine system, a bypass flow path is provided, which closes the reactor/sealing valve so that the exhaust gas from the exhaust gas collector is directed to the turbine without passing through the SCR reactor.

However, in the denitration system as described above, if the reducing agent flows into the turbine without passing through the reactor, there is a possibility that deposits derived from the reducing agent may be generated inside the turbine. In addition, there is also a possibility that the deposits may be generated in an exhaust economizer, a flue, etc. on the downstream side of the turbine. Furthermore, the reducing agent may flow out to the outside through the turbine.

The invention relates to an internal combustion engine, the purpose of which is to suppress the inflow of reducing agent to the downstream side of the reactor. [Technical means to solve the problem]

A preferred embodiment of the internal combustion engine of the present invention includes: an exhaust gas flow path for supplying exhaust gas flow; and a reducing agent supply unit that supplies the reducing agent to the exhaust gas flow path through nozzles attached to the exhaust gas flow path Exhaust gas mixing; reactor, where the exhaust gas flowing from the exhaust gas flow path is brought into contact with the catalyst to perform denitration; the flue duct guides the exhaust gas passing through the reactor; bypass the flow path, bypassing all The reactor connects the exhaust gas flow path to the flue; a bypass valve opens and closes the bypass flow path; a turbine is disposed in the reactor and the bypass flow path, and the Between the flues, the exhaust gas rotates; the compressor uses the rotation of the turbine as a power to pressurize the intake air; and the supply control unit, when detecting the valve opening process of the bypass valve, The reducing agent supply unit controls to stop the supply of the reducing agent to the exhaust gas flow path. With the bypass valve closed, the exhaust gas passing through the reactor flows into the turbine. With the bypass valve open, the exhaust gas passing through the reactor and the bypass flow path flows into the turbine. According to the internal combustion engine, it is possible to suppress the reducing agent from flowing into the downstream side of the reactor.

Preferably, the reducing agent supply unit includes: a reducing agent supply source that stores the reducing agent; piping that connects the reducing agent supply source to the nozzle; and a pump from the reducing agent supply source via the Piping to deliver the reducing agent to the nozzle; and a switching section provided on the piping to switch the delivery of the reducing agent delivered by the pump between the nozzle and other configurations than the nozzle Ground, and when the supply control unit detects the valve opening process of the bypass valve, it controls the switching unit so as to switch the delivery site of the reducing agent from the nozzle to the other configuration , Thereby stopping the supply of the reducing agent from the nozzle to the exhaust gas flow path.

Preferably, the other configuration is the reducing agent supply source or the piping on the upstream side of the switching unit.

It is preferable that the supply control unit controls the switching unit when the stop processing of the pump is detected, so as to switch the delivery position of the reducing agent from the nozzle to the other configuration.

Preferably, the reducing agent supply unit further includes a check valve, and the check valve is provided on the piping near the nozzle between the switching unit and the nozzle.

Preferably, it further includes a gas supply unit that supplies gas to the nozzle. After stopping the supply of the reducing agent from the nozzle to the exhaust gas flow path, the supply control unit controls the gas supply unit so that The nozzle supplies the gas.

Preferably, it further includes a cleaning liquid supply unit that supplies cleaning liquid to the nozzle, and after stopping the supply of the reducing agent from the nozzle to the exhaust gas flow path, the supply control unit controls the cleaning liquid supply unit So that the cleaning liquid is supplied to the nozzle, and the supply of the gas from the gas supply part to the nozzle starts from the beginning of the supply of the cleaning liquid from the cleaning liquid supply part to the nozzle. Start after the specified time.

It is preferable that when the supply control unit detects the valve closing process of the bypass valve in a state where the bypass valve is opened, the supply of the cleaning liquid supply unit to the nozzle is stopped after a predetermined time elapses The cleaning solution.

Preferably, the reducing agent supply unit includes: a reducing agent supply source that stores the reducing agent; piping that connects the reducing agent supply source to the nozzle; and a pump from the reducing agent supply source via the The piping conveys the reducing agent to the nozzle, and the supply control section stops the operation of the pump when detecting the valve opening process of the bypass valve, thereby stopping the nozzle from the nozzle The reducing agent is supplied to the exhaust gas flow path.

The invention also relates to a control system. The control system according to a preferred embodiment of the present invention controls the reducing agent supply unit in the internal combustion engine. The internal combustion engine includes: an exhaust gas flow path through which exhaust gas flows; and the reducing agent supply unit that supplies a reducing agent to the exhaust gas flow path through nozzles attached to the exhaust gas flow path and mixes with the exhaust gas; The degassing is carried out by contacting the exhaust gas flowing from the exhaust gas flow path with the catalyst; the flue duct is used to guide the exhaust gas passing through the reactor; the bypass flow path bypasses the reactor The exhaust gas flow path is connected to the flue; the bypass valve opens and closes the bypass flow path; the turbine is disposed between the reactor and the bypass flow path, and the flue, Rotation by exhaust gas; and compressor, which pressurizes intake air using the rotation of the turbine as power. With the bypass valve closed, the exhaust gas passing through the reactor flows into the turbine. With the bypass valve open, the exhaust gas passing through the reactor and the bypass flow path flows into the turbine. The control system includes: a detection unit that detects the valve opening process of the bypass valve; and a supply control unit that supplies the reducing agent when the detection unit detects the valve opening process of the bypass valve The unit controls to stop the supply of the reducing agent to the exhaust gas flow path. According to the control system, it is possible to suppress the inflow of reducing agent to the downstream side of the reactor.

The above-mentioned object and other objects, features, forms, and advantages are clarified by the following detailed description of the invention with reference to the drawings.

FIG. 1 is a diagram showing the configuration of an internal combustion engine 1 according to the first embodiment of the present invention. The internal combustion engine 1 is, for example, a diesel engine. In the example shown in FIG. 1, the internal combustion engine 1 is a two-stroke engine used as a main engine of a ship.

The internal combustion engine 1 includes a cylinder 2, a piston 3, a scavenging air flow path 41, an exhaust gas flow path 42, an air cooler 43, a supercharger 5, a denitration system 6, and a flue 81. The cylinder 2 is a substantially cylindrical member with a cover centered on a central axis extending in the vertical direction in FIG. 1. The piston 3 is a substantially cylindrical member having the center axis as its center, and its upper part is disposed inside the cylinder 2. The piston 3 can move in the vertical direction. Furthermore, the vertical direction in FIG. 1 does not necessarily need to be parallel to the direction of gravity.

The cylinder 2 includes a cylinder liner 21, a cylinder head 22, and an exhaust valve 25. The cylinder liner 21 is a substantially cylindrical member centered on the central axis. The cylinder head 22 is a covered substantially cylindrical member attached to the upper portion of the cylinder liner 21. An exhaust port 24 is formed in the top cover portion of the cylinder head 22. The exhaust port 24 is connected to the exhaust channel 42. The exhaust port 24 is opened and closed by an exhaust valve 25. As shown by the solid line in FIG. 1, the exhaust valve 25 is separated downward from the exhaust port 24 and the exhaust port 24 is opened. In addition, as indicated by the two-dot chain line in FIG. 1, the exhaust valve 25 contacts the cylinder head 22 and overlaps the exhaust port 24, and the exhaust port 24 is closed. A scavenging port 23 is provided near the lower end of the cylinder liner 21. The scavenging port 23 is a collection of a plurality of through-holes formed on the side surface of the cylinder liner 21 in a circumferential arrangement. The scavenging port 23 is connected to the scavenging air channel 41.

The piston 3 has a piston head 31 and a piston rod 32. The piston head 31 is a thick, substantially disc-shaped portion centered on the central axis. The piston head 31 is arranged inside the cylinder liner 21. The piston rod 32 is a substantially cylindrical portion extending downward from the lower surface of the piston head 31. The lower end of the piston rod 32 is connected to a crank mechanism (not shown). With the crank mechanism, the piston 3 reciprocates in the up-down direction. In FIG. 1, the piston 3 located at the bottom dead center of the reciprocating movement is depicted by a solid line, and the piston 3 located at the top dead center is depicted by a two-dot chain line.

In the internal combustion engine 1, the space surrounded by the upper surface of the cylinder liner 21, the cylinder head 22, the exhaust valve 25, and the piston head 31 (that is, the upper surface of the piston 3) is a combustion chamber 20 for burning fuel and air .

Via the scavenging port 23, scavenging gas is supplied from the scavenging air flow path 41 to the combustion chamber 20. The scavenging air flow path 41 includes a scavenging chamber 411 and a scavenging collector 412. The scavenging chamber 411 is a space (ie, scavenging piping) provided around the scavenging port 23 of the cylinder liner 21. The scavenging port 23 communicates with the scavenging collector 412 via the scavenging chamber 411. The scavenging concentrator 412 is a substantially cylindrical large-sized container that supplies scavenging gas to the scavenging chamber 411.

The gas (ie, combustion gas) generated by the combustion of fuel and air in the combustion chamber 20 is discharged to the exhaust gas flow path 42 through the exhaust port 24. The exhaust gas flow path 42 is a pipe through which gas (hereinafter referred to as “exhaust gas”) discharged from the combustion chamber 20 flows. The exhaust flow path 42 includes an exhaust pipe 421 and an exhaust collector 422. The exhaust pipe 421 is a pipe that connects the exhaust port 24 and the exhaust collector 422. The exhaust gas collector 422 is a substantially cylindrical large container that receives exhaust gas from the combustion chamber 20. In addition, the combustion chamber 20 may also be understood as a part of the exhaust flow path 42 through which exhaust gas flows.

In the internal combustion engine 1, a plurality of sets of cylinders 2 and pistons 3 are provided. As shown in FIG. 2, a plurality of combustion chambers 20 are connected to one scavenging collector 412 and one exhaust collector 422. That is, the scavenging collector 412 is a scavenging manifold for distributing and supplying scavenging gas to the plurality of combustion chambers 20. In addition, the exhaust collector 422 is an exhaust manifold (also referred to as an exhaust manifold) that collects exhaust gas discharged from the plurality of combustion chambers 20. Since the exhaust gas from the plurality of combustion chambers 20 is sequentially sent to the exhaust gas collector 422 at different timings, a turbulent flow of exhaust gas is formed in the exhaust gas collector 422.

The exhaust gas collected in the exhaust gas collector 422 is denitrified by the denitration system 6 shown in FIG. 1 and then sent to the supercharger 5. The denitration treatment by the denitration system 6 will be described later. The supercharger 5 is a turbocharger including a turbine 51 and a compressor 52. In the supercharger 5, the intake air is pressurized with exhaust gas to generate scavenging gas.

Specifically, the turbine 51 rotates by the exhaust gas sent from the exhaust gas collector 422 to the supercharger 5. The exhaust gas used for the rotation of the turbine 51 is guided to the flue 81 and is discharged from the flue 81 to the outside of the internal combustion engine 1. The compressor 52 pressurizes and compresses intake air (air) taken in from the outside of the internal combustion engine 1 via the intake path 82 using the rotational force generated by the turbine 51 (that is, using the rotation of the turbine 51 as power). The pressurized air (that is, the scavenging gas) is cooled by the air cooler 43, and then supplied to the scavenging gas collector 412 and supplied from the scavenging gas collector 412 to each combustion chamber 20.

FIG. 3 is a diagram showing a part of the configuration of the denitration system 6. In FIG. 3, the configuration other than the denitration system 6 is also shown. As shown in FIGS. 1 and 3, the denitration system 6 includes a nozzle 61, a common pipe 62, a reducing agent supply part 63, a cleaning liquid supply part 64, a gas supply part 65, a reactor 66, an SCR flow path 67, and a bypass The flow path 681, the bypass valve 682, and the control system 70.

The control system 70 is, for example, a programmable logic controller (Programmable Logic Controller, PLC). The PLC includes: a processor, a memory, an input and output unit, and a bus. The bus is a signal circuit that connects the processor, memory, and input/output units. The memory stores programs and various information. The processor executes various kinds of processing (for example, numerical calculation, etc.) while using the memory or the like based on a program or the like stored in the memory. The input/output unit receives input from an operator and signal input from other devices, and outputs signals to other devices. The PLC performs processing based on a predetermined program, thereby realizing each function of the control system 70 (for example, the detection unit 71 and the supply control unit 72). The detection unit 71 is mainly realized by a processor, and detects a valve opening process and a valve closing process to be described later of the bypass valve 682. The supply control unit 72 is mainly realized by a processor, and controls the reducing agent supply unit 63 and the like. The control system 70 may be a general computer system including a keyboard and a display, or it may be a circuit board or the like. Furthermore, the illustration of the control system 70 is omitted in FIG. 1.

The nozzle 61 is attached to the exhaust collector 422 in the exhaust flow path 42. The nozzle 61 is connected to the reducing agent supply part 63, the cleaning liquid supply part 64, and the gas supply part 65 via the common pipe 62. The reducing agent supply unit 63, the cleaning liquid supply unit 64, and the gas supply unit 65 are controlled by the supply control unit 72 of the control system 70. The reducing agent supply unit 63 is driven during the denitration process of the exhaust gas. The cleaning liquid supply unit 64 and the gas supply unit 65 are driven when the denitration process is stopped, and are used for cleaning the nozzle 61 and the like.

The reducing agent supply unit 63 supplies the reducing agent for the denitration treatment of the exhaust gas to the nozzle 61. As the reducing agent, urea water (CO(NH ₂ ) ₂ ) or ammonia water (NH ₃ ) can be used. In this embodiment, urea water is used as a reducing agent. The reducing agent supply unit 63 includes a reducing agent supply source 631, a reducing agent piping 632, a reducing agent pump 633, a switching unit 634, a check valve 635, and a circulation channel 636. The reducing agent supply source 631 is, for example, a storage tank that stores the reducing agent. The reducing agent piping 632 is a piping that connects the reducing agent supply source 631 and the nozzle 61. The reducing agent pump 633 is a pump that sends the reducing agent to the nozzle 61 from the reducing agent supply source 631 through the reducing agent piping 632. The flow rate of the reducing agent delivered to the nozzle 61 by the reducing agent pump 633 is, for example, several liters/hour to several hundreds of liters/hour. The reducing agent pump 633 is, for example, an inverter pump.

The switching unit 634 is provided on the reducing agent pipe 632 between the reducing agent pump 633 and the nozzle 61. The switching unit 634 is, for example, a solenoid valve. One end of the circulation channel 636 is connected to the switching unit 634. The other end of the circulation flow path 636 is connected to the reducing agent supply source 631. The other end of the circulation channel 636 may be connected to the reducing agent piping 632 between the reducing agent supply source 631 and the reducing agent pump 633 or between the reducing agent pump 633 and the switching unit 634. In other words, the other end portion of the circulation flow path 636 may be connected to the reducing agent piping 632 on the upstream side of the switching portion 634.

In the state shown in FIG. 3, the reducing agent sent from the reducing agent pump 633 to the switching unit 634 is supplied to the nozzle 61 via the switching unit 634, the reducing agent piping 632, the check valve 635, and the common piping 62. The reducing agent does not flow from the switching unit 634 to the circulation channel 636. On the other hand, when the switching unit 634 is switched, the reducing agent sent from the reducing agent pump 633 to the switching unit 634 is not supplied to the nozzle 61, but is circulated to the reducing agent supply source 631 (or the reducing agent piping 632) via the circulation flow path 636 . In other words, the switching unit 634 switches the delivery location of the reducing agent delivered by the reducing agent pump 633 between the nozzle 61 and other configurations other than the nozzle 61 (ie, the reducing agent supply source 631 or the reducing agent piping 632).

The check valve 635 is provided on the reducing agent piping 632 near the nozzle 61 between the nozzle 61 and the switching portion 634. In detail, the check valve 635 is disposed near the junction of the reducing agent piping 632 and the common piping 62 and the switching portion 634. The check valve 635 prevents the fluid from flowing back to the switching portion 634 from the confluence point side.

The cleaning liquid supply unit 64 supplies the cleaning liquid for cleaning the nozzle 61 to the nozzle 61. As the cleaning liquid, clean water used for other purposes in ships can be used. Furthermore, liquids other than clean water can also be used as cleaning liquids. The cleaning liquid supply unit 64 includes a cleaning liquid supply source 641, a cleaning liquid pipe 642, a cleaning liquid pump 643, and a check valve 645. The cleaning liquid supply source 641 is, for example, a storage tank that stores cleaning liquid. The cleaning liquid pipe 642 is a pipe that connects the cleaning liquid supply source 641 to the nozzle 61. The cleaning liquid pump 643 is a pump that sends the cleaning liquid to the nozzle 61 from the cleaning liquid supply source 641 via the cleaning liquid pipe 642.

The check valve 645 is provided on the cleaning liquid pipe 642 between the nozzle 61 and the cleaning liquid pump 643 near the nozzle 61. Specifically, the check valve 645 is arranged near the junction of the cleaning fluid pipe 642 and the common pipe 62 and the cleaning fluid pump 643. The check valve 645 prevents the fluid from flowing backward from the confluence point side to the cleaning liquid pump 643.

The gas supply unit 65 supplies the nozzle 61 with gas for cleaning the nozzle 61 and for promoting the exhaust gas transport from the exhaust collector 422. As the gas, compressed air (for example, air with a pressure of several hundred kPa to several MPa) or the like can be used. In addition, gas other than compressed air may be supplied from the gas supply unit 65 to the nozzle 61. The gas supply unit 65 includes a gas supply source 651, a gas piping 652, a gas supply valve 653, and a check valve 655. The gas supply source 651 is, for example, a storage tank that stores compressed air. The gas piping 652 is a piping that connects the gas supply source 651 and the nozzle 61. The gas supply valve 653 is provided in the gas piping 652 and supplies gas from the gas supply source 651 to the nozzle 61 by opening the valve. In addition, by closing the gas supply valve 653, the gas supply to the nozzle 61 is stopped. Furthermore, instead of the gas supply source 651 and the gas supply valve 653, a blower that compresses and delivers air may be provided.

The check valve 655 is provided between the nozzle 61 and the gas supply valve 653 in the gas piping 652 near the nozzle 61. In detail, the check valve 655 is disposed near the junction of the gas piping 652 and the common piping 62 and the gas supply valve 653. The check valve 655 prevents the fluid from flowing back to the gas supply valve 653 and the gas supply source 651 from the confluence point side.

The SCR flow path 67 is a pipeline that connects the exhaust collector 422 of the exhaust flow path 42 and the turbine 51 of the supercharger 5. The reactor 66 is provided on the SCR flow path 67. In the reactor 66, a catalyst for denitration treatment of exhaust gas is housed. In the reactor 66, denitration treatment of the exhaust gas by the SCR (Selective catalytic reduction) method is performed.

The bypass flow path 681 is a pipeline that branches off in the middle of the SCR flow path 67 and bypasses the junction of the reactor 66 and the SCR flow path 67. In other words, the bypass flow path 681 connects the exhaust gas collector 422 of the exhaust flow path 42 to the turbine 51 and the flue 81 of the supercharger 5 bypassing the reactor. Specifically, the bypass flow path 681 branches from the SCR flow path 67 between the exhaust gas collector 422 and the reactor 66, and merges with the SCR flow path 67 between the reactor 66 and the turbine 51. The bypass valve 682 is provided on the bypass flow path 681 for opening and closing the bypass flow path 681. The bypass valve 682 is driven by, for example, a drive control unit (not shown) of the internal combustion engine 1.

In the state where the denitration process of the exhaust gas is performed in the denitration system 6, as shown in FIG. 4, the reducing agent pump 633 and the nozzle 61 are connected through the switching unit 634 of the reducing agent supply unit 63, and from The reducing agent sent from the reducing agent supply source 631 is continuously supplied to the exhaust gas collector 422 via the switching unit 634, the reducing agent piping 632, the check valve 635, the common piping 62, and the nozzle 61. The spray gas is supplied to the nozzle 61 from a spray gas supply unit (not shown), and the reducing agent from the nozzle 61 is supplied into the exhaust gas collector 422 in a state of being atomized by the spray gas (that is, in the form of a mist). The supply amount of the reducing agent is controlled based on the content of nitrogen oxides in the exhaust gas and the like. In addition, in the state where the reducing agent is supplied to the nozzle 61, the cleaning liquid pump 643 of the cleaning liquid supply part 64 is stopped, and since the gas supply valve 653 of the gas supply part 65 is closed, the cleaning liquid and compressed air are not supplied to Nozzle 61. In FIG. 4, the path through which the reducing agent flows is depicted by a solid line, and the other paths of unflowed fluid are depicted by a dotted line (the same is true in FIG. 8 ).

The reducing agent (ie, urea water) supplied from the nozzle 61 to the exhaust gas collector 422 is mixed with the exhaust gas. As described above, in the exhaust gas collector 422, since the exhaust gas from each exhaust pipe 421 flows in to form a turbulent flow of the exhaust gas, the reducing agent and the exhaust gas are efficiently mixed. In the exhaust gas collector 422, urea mixed with high-temperature exhaust gas is thermally decomposed to generate ammonia and isocyanic acid (HNCO). In addition, isocyanic acid is hydrolyzed to produce ammonia. The exhaust gas mixed with ammonia is sent from the exhaust gas collector 422 to the SCR flow path 67.

In the state where the denitration treatment of the exhaust gas is performed, the bypass valve 682 is closed, and as shown in FIG. 5, the exhaust gas (ie, the exhaust gas containing ammonia) sent from the exhaust gas collector 422 to the SCR flow path 67 flows in To reactor 66 and contact with the catalyst. As a result, nitrogen oxides (NO _x ) in the exhaust gas react with ammonia to be reduced and decompose into nitrogen (N ₂ ) and water (H ₂ O). The exhaust gas that has passed the denitration treatment passing through the reactor 66 is supplied to the turbine 51 disposed between the reactor 66 and the flue 81 through the SCR flow path 67. The turbine 51 rotates using the exhaust gas from the reactor 66. The exhaust gas passing through the turbine 51 is guided to the flue 81 and is discharged from the flue 81 to the outside of the internal combustion engine 1. In addition, in FIG. 5, the path of unflowed exhaust gas (that is, the bypass flow path 681) is depicted by a broken line.

On the other hand, when the bypass valve 682 is opened, as shown in FIG. 6, the exhaust gas sent from the exhaust gas collector 422 to the SCR flow path 67 flows through the reactor 66 and the bypass flow path 681 and is supplied to the reactor. 66 and the bypass flow path 681, and the turbine 51 between the flue 81. In other words, the exhaust gas passing through the reactor 66 and the exhaust gas that does not flow into the reactor 66 (that is, bypasses the reactor 66) and passes through the bypass flow path 681 flow into the turbine 51. The turbine 51 rotates using the exhaust gas from the reactor 66 and the bypass flow path 681. The exhaust gas passing through the turbine 51 is guided to the flue 81 and is discharged from the flue 81 to the outside of the internal combustion engine 1.

The opening of the bypass valve 682 is performed, for example, when the temperature of the exhaust gas at the inlet of the turbine 51 is insufficient when the ship accelerates. Specifically, for example, the drive control unit obtains the exhaust gas temperature at the inlet of the SCR channel 67 and the exhaust gas temperature at the inlet of the turbine 51, and when the difference between the two temperatures is equal to or greater than a predetermined threshold, The bypass valve 682 is opened by the drive control unit. In the state where the bypass valve 682 is opened, the exhaust gas passing through the bypass flow path 681 flows into the turbine 51, so the temperature of the exhaust gas at the inlet of the turbine 51 can be increased.

In the internal combustion engine 1, in a state where the bypass valve 682 is open, in order to prevent the reducing agent from flowing into the turbine 51 without passing through the reactor 66, the supply of reducing agent from the nozzle 61 to the exhaust gas collector 422 is stopped. It is assumed that when the reducing agent flows into the turbine 51, solids derived from the reducing agent may be generated and accumulated in the turbine 51 due to temperature conditions or the like. In addition, ammonia generated from urea may be discharged from the flue 81 to the outside of the internal combustion engine 1 (that is, ammonia loss occurs).

Hereinafter, the flow of stopping the supply of the reducing agent will be described with reference to FIG. 7. First, when it is determined that the bypass valve 682 in the valve-closed state needs to be opened by the drive control unit described above, the valve opening process of the bypass valve 682 is started (step S11). Specifically, a valve opening command (also referred to as a valve opening signal) is issued from the drive control unit to the pneumatic actuator that is the drive unit of the bypass valve 682. Furthermore, the pressure inside the pneumatic actuator rises, and after a predetermined time has elapsed since the valve opening command was issued, the bypass valve 682 opens the valve at a predetermined opening degree. The predetermined time is a time lag required for driving the so-called bypass valve 682, for example, about 3 seconds. In the internal combustion engine 1, during the time lag, the following steps S12 to S15 are executed.

The detection unit 71 of the control system 70 continues to monitor the valve opening process and valve closing process of the bypass valve 682. When detecting the valve opening process of the bypass valve 682, the detection unit 71 sends a signal to the supply control unit 72 to notify the start of the valve opening process. When the detection unit 71 detects the valve opening process of the bypass valve 682, the supply control unit 72 controls the reducing agent supply unit 63 to stop the supply of the reducing agent from the nozzle 61 to the exhaust collector 422 (step S12).

Specifically, the detection unit 71 detects the valve opening command sent from the drive control unit to the bypass valve 682, and detects the start of the valve opening process of the bypass valve 682. Furthermore, the supply control unit 72 controls the switching unit 634 of the reducing agent supply unit 63 to disconnect the reducing agent pump 633 and the nozzle 61 as shown in FIG. 8, and connect the reducing agent pump 633 and the circulation channel 636 . Since the reducing agent pump 633 continues to operate, the reducing agent sent from the reducing agent pump 633 from the reducing agent supply source 631 returns to the reducing agent supply source 631 via the circulation flow path 636 (or the reducing agent piping 632 upstream of the switching unit 634) . In other words, the reducing agent sent from the reducing agent pump 633 is not supplied to the nozzle 61, but circulates in the reducing agent supply unit 63. In addition, the operation of the reducing agent pump 633 is continuously continued from step S11 to step S20 (described later).

In this manner, the supply control unit 72 switches the delivery position of the reducing agent sent from the reducing agent pump 633 from the nozzle 61 to a configuration other than the nozzle 61 (that is, the reducing agent supply source 631 or the reducing agent piping 632), thereby stopping from The nozzle 61 supplies the reducing agent to the exhaust gas collector 422. Furthermore, the detection unit 71 can detect the start of the valve opening process of the bypass valve 682 by detecting the pressure change inside the pneumatic actuator that is the driving unit of the bypass valve 682. In this case, the detection unit 71 may include a sensor that measures the pressure inside the pneumatic actuator, and/or a receiving unit that receives the measured value measured by the sensor. In addition, the driving part of the bypass valve 682 may be a mechanism other than a pneumatic actuator (for example, a hydraulic actuator or an electric actuator).

When the supply of the reducing agent from the nozzle 61 to the exhaust gas collector 422 is stopped, the supply control unit 72 controls the cleaning liquid supply unit 64 to start supply of cleaning liquid such as clean water to the nozzle 61 (step S13). Specifically, the cleaning liquid pump 643 of the cleaning liquid supply unit 64 is driven by the supply control unit 72, and the cleaning liquid is supplied from the cleaning liquid supply source 641 to the nozzle 61. The cleaning liquid is discharged from the nozzle 61 together with the reducing agent remaining in the common pipe 62 and the nozzle 61, and is supplied into the exhaust collector 422 in a state of being atomized by the gas for spraying. As a result, the reducing agent remaining inside the common pipe 62 and the nozzle 61 is washed and replaced with a cleaning liquid. In this way, by cleaning the common pipe 62 and the nozzle 61, it is possible to prevent or suppress solid matter derived from the reducing agent from accumulating on the common pipe 62 or the nozzle 61 and clogging the nozzle 61.

Then, the gas supply part 65 is controlled by the supply control part 72, and the supply of gas, such as compressed air, to the nozzle 61 is started (step S14). Specifically, the gas supply valve 653 of the gas supply unit 65 is opened by the supply control unit 72, and the gas is sent to the nozzle 61 via the common pipe 62. At this time, the cleaning liquid is continuously supplied from the cleaning liquid supply unit 64 to the nozzle 61, and the gas is sprayed from the nozzle 61 into the exhaust collector 422 together with the cleaning liquid. As a result, the common pipe 62 and the nozzle 61 are further washed, and the reducing agent in the common pipe 62 and the nozzle 61 is substantially completely removed. That is, the gas supplied from the gas supply part 65 to the nozzle 61 is a flushing gas for discharging the reducing agent from the nozzle 61.

It is preferable that the gas supply from the gas supply part 65 to the nozzle 61 is started from the time when the cleaning liquid supply part 64 supplies the cleaning liquid to the nozzle 61 (step S13), and a predetermined time (for example, about 1 second) starts. . Before the gas is supplied to the common pipe 62 and the nozzle 61, the reducing agent in the common pipe 62 and the nozzle 61 is flushed to some extent by the cleaning liquid (ie, the reducing agent is diluted with the cleaning liquid), thereby preventing remaining in the common pipe 62 The reducing agent in the nozzle 61 is largely discharged into the exhaust gas collector 422 in a very short time by the gas from the gas supply unit 65 (that is, the excessive supply of the reducing agent). The time difference between the start of the cleaning liquid supply and the start of the gas supply is realized by, for example, a delay timer.

After a predetermined time (for example, about 2 seconds) has elapsed since the start of the gas supply in step S14, the gas supply valve 653 is closed to stop the gas supply from the gas supply unit 65 to the nozzle 61 (step S15). The supply of the gas from the gas supply part 65 to the nozzle 61 ends before the valve opening process of the bypass valve 682 ends and the bypass valve 682 is actually opened (step S16). Alternatively, the supply of gas from the gas supply unit 65 may be stopped (step S15) simultaneously with the end of the valve opening process of the bypass valve 682 (step S16). In other words, as described above, steps S14 and S15 are performed during the time lag (for example, about 3 seconds) from when the valve opening command of the bypass valve 682 is issued to when it is actually opened. Thereby, before the bypass valve 682 is actually opened, the reducing agent in the nozzle 61 can be pushed out to the exhaust gas collector 422, and the exhaust gas flowing from each exhaust pipe 421 can reduce the reduction agent in the exhaust gas collector 422. The agent is pushed out to the SCR flow path 67.

After a predetermined time (for example, 15 seconds) has elapsed since the gas supply from the gas supply unit 65 was stopped, the driving of the cleaning liquid pump 643 is stopped, thereby stopping the supply of the cleaning liquid from the cleaning liquid supply unit 64 to the nozzle 61 (step S17). Thereafter, while the bypass valve 682 is in the valve-open state, the reducing agent, the cleaning liquid, and the gas are not supplied from the nozzle 61 to the exhaust gas collector 422.

Then, when it is determined that the bypass valve 682 in the valve-open state needs to be closed by the drive control unit described above, the valve closing process of the bypass valve 682 is started (step S18). Specifically, a valve closing command (also referred to as a valve closing signal) is issued from the drive control unit to the drive unit of the bypass valve 682. The bypass valve 682 is closed after a predetermined time (ie, time lag) has elapsed since the valve closing command was issued. In other words, the valve closing process of the bypass valve 682 ends (step S19).

When the detection unit 71 detects the valve closing command of the bypass valve 682, the supply control unit 72 controls the reducing agent supply unit 63 after a predetermined time (for example, about 10 seconds) has elapsed since the valve closing process was detected, and restarts The reducing agent is supplied to the nozzle 61 (step S20). Specifically, the switching unit 634 switches from the state shown in FIG. 8 to the state shown in FIG. 4, and switches the delivery place of the reducing agent from the reducing agent pump 633 from the reducing agent supply source 631 (or reducing agent piping 632) to Nozzle 61.

The predetermined time is set to start supplying the reducing agent to the nozzle 61 after the bypass valve 682 is actually closed (that is, after the time lag). This prevents the reducing agent from being supplied to the exhaust gas collector 422 in a state where the bypass valve 682 has not been closed. As a result, the exhaust gas including the reducing agent and the like is prevented from flowing into the turbine 51 and the flue 81 through the bypass flow path 681. Furthermore, the detection unit 71 can detect the start of the valve closing process of the bypass valve 682 by detecting the pressure change inside the pneumatic actuator or the like that is the driving unit of the bypass valve 682. The time difference between the detection of the valve closing process and the start of the supply of the reducing agent is realized by, for example, a delay timer.

As described above, the internal combustion engine 1 includes the exhaust flow path 42, the reducing agent supply portion 63, the reactor 66, the flue 81, the bypass flow path 681, the bypass valve 682, the turbine 51, the compressor 52, and the supply Controller 72. In the exhaust gas flow path 42, exhaust gas flows. The reducing agent supply unit 63 supplies the reducing agent to the exhaust gas flow path 42 via the nozzle 61 attached to the exhaust gas flow path 42 and mixes it with the exhaust gas. The reactor 66 brings the exhaust gas flowing in from the exhaust gas flow path 42 into contact with the catalyst to perform denitration treatment. The exhaust gas passing through the reactor 66 is directed to the flue 81. The bypass flow path 681 bypasses the reactor 66 and connects the exhaust flow path 42 to the flue 81. The bypass valve 682 opens and closes the bypass flow path 681. The turbine 51 is disposed between the reactor 66 and the bypass flow path 681, and the flue 81, and is rotated by exhaust gas. The compressor 52 uses the rotation of the turbine 51 as power to pressurize the intake air. When detecting the valve opening process of the bypass valve 682, the supply control unit 72 controls the reducing agent supply unit 63 to stop supplying the reducing agent to the exhaust flow path 42. With the bypass valve 682 closed, the exhaust gas passing through the reactor 66 flows into the turbine 51. With the bypass valve 682 open, the exhaust gas passing through the reactor 66 and the bypass flow path 681 flows into the turbine 51.

In the internal combustion engine 1 described above, it is possible to suppress the flow of reducing agent into the downstream side of the reactor 66. Specifically, it is possible to suppress the reducing agent from flowing into the turbine 51 and the flue 81 that are located downstream of the reactor 66 in the flow of exhaust gas. As a result, it is possible to prevent or suppress the generation of deposits derived from the reducing agent in the turbine 51 and the flue 81 that are downstream devices of the reactor 66. In addition, leakage of the reducing agent to the outside of the internal combustion engine 1 can also be prevented or suppressed.

As described above, it is preferable that the reducing agent supply unit 63 includes a reducing agent supply source 631, a reducing agent piping 632, a reducing agent pump 633, and a switching unit 634. The reducing agent supply source 631 stores the reducing agent. The reducing agent piping 632 is a piping that connects the reducing agent supply source 631 and the nozzle 61. The reducing agent pump 633 sends the reducing agent from the reducing agent supply source 631 to the nozzle 61 via the reducing agent piping 632. The switching unit 634 is provided on the reducing agent piping 632. The switching unit 634 switches the delivery location of the reducing agent delivered by the reducing agent pump 633 between the nozzle 61 and other configurations than the nozzle 61. When detecting the valve opening process of the bypass valve 682, the supply control unit 72 controls the switching unit 634 to switch the delivery position of the reducing agent from the nozzle 61 to the other configuration, thereby stopping the exhaust from the nozzle 61 The flow path 42 is supplied with a reducing agent.

Thereby, the supply of the reducing agent to the exhaust flow path 42 can be stopped without stopping the reducing agent pump 633. As a result, it is possible to simplify the control of the denitration system 6 when the supply of the reducing agent to the exhaust flow path 42 is stopped. In addition, since it is possible to prevent the reducing agent pump 633 from being repeatedly started, the life of the reducing agent pump 633 can be extended. Furthermore, the nozzle 61 can be understood as a part of the reducing agent supply part 63.

More preferably, the other configuration described above is the reducing agent supply source 631 or the reducing agent piping 632 upstream of the switching unit 634. Thereby, when the supply of reducing agent to the exhaust flow path 42 is stopped, the reducing agent sent from the reducing agent pump 633 can be circulated in the reducing agent supply unit 63. As a result, it is possible to reduce the amount of the reducing agent used in the internal combustion engine 1 compared with the case where the reducing agent sent from the reducing agent pump 633 is discarded (that is, compared with the case where the other structure is configured as a drain pipe).

As described above, it is preferable that the internal combustion engine 1 further includes the gas supply part 65. The gas supply unit 65 supplies gas to the nozzle 61. In the internal combustion engine 1, after the supply of the reducing agent from the nozzle 61 to the exhaust flow path 42 is stopped, the supply control unit 72 controls the gas supply unit 65 to supply gas to the nozzle 61.

Thereby, the nozzle 61 after the supply of the reducing agent is stopped can be appropriately cleaned (that is, the cleaning process). As a result, it is possible to prevent or suppress clogging of the nozzle 61 due to accumulation of solids derived from the reducing agent.

As described above, it is preferable that the internal combustion engine 1 further includes the cleaning liquid supply part 64. The cleaning liquid supply unit 64 supplies the cleaning liquid to the nozzle 61. In the internal combustion engine 1, after the supply of the reducing agent from the nozzle 61 to the exhaust flow path 42 is stopped, the supply control unit 72 controls the cleaning liquid supply unit 64 to supply the cleaning liquid to the nozzle 61. It is preferable that the supply of gas from the gas supply part 65 to the nozzle 61 starts from the time when the cleaning liquid supply part 64 supplies the cleaning liquid to the nozzle 61 and starts after a predetermined time. Accordingly, it is possible to prevent the reducing agent remaining in the nozzle 61 from being discharged into the exhaust gas collector 422 in a large amount of time by the gas (ie, excessive supply of the reducing agent). As a result, it is possible to suppress the reducing agent and the like from passing through the reactor 66 in an unreacted state and flowing into the turbine 51 and the flue 81.

As described above, it is preferable that the reducing agent supply part 63 further includes a check valve 635. The check valve 635 is provided on the reducing agent piping 632 near the nozzle 61 between the switching portion 634 and the nozzle 61. This can prevent the fluid from flowing back from the nozzle 61 side to the switching portion 634. In addition, when the nozzle 61 is cleaned by the cleaning liquid supply part 64 and the gas supply part 65 described above, by arranging the check valve 635 near the nozzle 61, the amount of the reducing agent that needs to be rinsed during cleaning can be reduced (ie, The amount of reducing agent remaining between the nozzle 61 and the check valve 635). As a result, the time required for cleaning the nozzle 61 can be shortened, the reducing agent in the nozzle 61 can be pushed out to the exhaust collector 422 before the bypass valve 682 is actually opened, and the The exhaust gas pushes the reducing agent in the exhaust gas collector 422 to the SCR flow path 67. The piping length from the check valve 635 to the nozzle 61 is preferably within 3 m, and more preferably within 2 m.

As described above, it is preferable that the exhaust gas flow path 42 includes an exhaust gas collector 422 that collects the exhaust gas discharged from the combustion chamber 20 and the exhaust gas discharged from the other combustion chamber 20 and from the nozzle 61 supplies a reducing agent to the exhaust gas collector 422. Thereby, the turbulent flow formed in the exhaust gas collector 422 due to the exhaust gas sequentially delivered from the plurality of combustion chambers 20 can be utilized, and the mixing of the reducing agent and the exhaust gas can be efficiently performed. As a result, the denitration process using the exhaust gas of the denitration system 6 can be suitably performed.

In the internal combustion engine 1, there are cases where the opening and closing of the bypass valve 682 is repeated for a short period of time due to load fluctuations of the internal combustion engine 1 due to the influence of the ocean phenomenon. For example, there is a possibility that the valve closing process of the bypass valve 682 (step S18) starts immediately after the valve opening process of the bypass valve 682 in step S16 (for example, a few seconds later), and the bypass valve in step S19 After the valve closing process of 682 is completed, the valve opening process of the bypass valve 682 is started immediately (for example, a few seconds later) (step S11).

In the internal combustion engine 1, when the supply control unit 72 detects the valve closing process of the bypass valve 682 while the bypass valve 682 is open, the supply of the cleaning liquid from the cleaning liquid supply unit 64 to the nozzle 61 is stopped after a predetermined time has passed. Therefore, when the valve opening process of the bypass valve 682 that temporarily closes is restarted before the predetermined time (for example, about 10 seconds) elapses, the cleaning liquid supply unit 64 continues to supply the cleaning to the nozzle 61 Liquid, the nozzle 61 can be cleaned without changing the operation of the cleaning liquid pump 643. In other words, even when the opening and closing of the bypass valve 682 is repeated in a short time, it is possible to suppress repeated activation of the cleaning liquid pump 643 in a short time. As a result, the life of the cleaning liquid pump 643 (that is, the driving unit of the cleaning liquid supply unit 64) can be extended. Furthermore, the time difference between the detection of the valve closing process and the stop of the supply of the cleaning liquid is realized by, for example, a delay timer.

In addition, as described above, when the supply control unit 72 detects the valve closing process of the bypass valve 682 when the bypass valve 682 is open, the supply of the reducing agent from the reducing agent supply unit 63 to the nozzle 61 starts after a predetermined time elapses . Therefore, when the valve opening process of the bypass valve 682 that temporarily closes is restarted before the predetermined time (for example, about 10 seconds) elapses, the supply of the reducing agent from the reducing agent supply unit 63 to the nozzle 61 is still stopped. Thus, even when the opening and closing of the bypass valve 682 is repeated in a short time, it is possible to suppress the supply of the reducing agent to the exhaust gas collector 422 with the bypass valve 682 open, and the discharge including the reducing agent and the like The gas flows into the turbine 51 and the flue 81 through the bypass flow path 681.

In the internal combustion engine 1, when a certain abnormality occurs, the denitration system 6 opens the bypass valve 682 and stops the reducing agent pump 633 (so-called SCR off or SCR stop). In this case, the supply of the reducing agent to the nozzle 61 is stopped by starting the valve opening process of the bypass valve 682 (step S11) and stopping the operation of the reducing agent pump 633 (step S12). That is, when the SCR is turned off or the SCR is stopped, when the supply control unit 72 detects the valve opening process of the bypass valve 682 and/or the stopping process of the reducing agent pump 633, the supply of the reducing agent to the nozzle 61 is stopped. Thus, it is possible to suppress the inflow of the reducing agent to the downstream side of the reactor 66. Thereafter, the nozzle 61 and the common pipe 62 are cleaned.

In the internal combustion engine 1, it is preferable that the supply control unit 72 controls the switching unit 634 when detecting the stop process of the reducing agent pump 633, and switches the delivery place of the reducing agent from the nozzle 61 to the other configuration (for example, Reducing agent supply source 631 or reducing agent piping 632). As a result, it is possible to prevent or suppress the reducing agent remaining in the reducing agent piping 632 from the reducing agent pump 633 to the switching section 634 from moving to the nozzle 61 side and leaking from the nozzle 61 when the SCR is turned off (ie, from the nozzle 61) Droplets of the reducing agent).

Next, the internal combustion engine 1a according to the second embodiment of the present invention will be described. 9 is a diagram showing a part of the configuration of the denitration system 6a of the internal combustion engine 1a. The internal combustion engine 1a has the same structure as the internal combustion engine 1 shown in FIG. 1 except that the switching portion 634 is omitted from the reducing agent supply portion 63. In the following description, each configuration of the internal combustion engine 1a is denoted by the same reference symbol as the configuration corresponding to the internal combustion engine 1.

In the internal combustion engine 1a, the reducing agent supply unit 63 includes a reducing agent supply source 631, a reducing agent piping 632, and a reducing agent pump 633. Similar to the internal combustion engine 1 described above, the reducing agent supply source 631 stores the reducing agent. The reducing agent piping 632 is a piping that connects the reducing agent supply source 631 and the nozzle 61. The reducing agent pump 633 sends the reducing agent from the reducing agent supply source 631 to the nozzle 61 via the reducing agent piping 632.

In the internal combustion engine 1a, the operations during the valve opening process and the valve closing process of the bypass valve 682 (see FIG. 1) are substantially the same as steps S11 to S20 shown in FIG. 7. However, in the internal combustion engine 1a, the supply of the reducing agent in step S12 is not stopped by the switching unit 634 switching the supply of the reducing agent, but by stopping the reducing agent pump 633.

Specifically, when detecting the valve opening process of the bypass valve 682, the supply control unit 72 stops the operation of the reducing agent pump 633, thereby stopping the supply of the reducing agent from the nozzle 61 to the exhaust passage 42. Thereby, the supply of the reducing agent to the exhaust flow path 42 can be stopped with a simple structure. In addition, the structure of the internal combustion engine 1a is the same as that of the internal combustion engine 1, and is particularly suitable for an internal combustion engine in which a turbine 51 is provided downstream of the reactor 66.

Various changes can be made to the internal combustion engine 1 and the internal combustion engine 1a.

For example, in the reducing agent supply part 63 of the denitration system 6, the check valve 635 may be omitted. Similarly, in the cleaning liquid supply unit 64 and the gas supply unit 65, the check valve 645 and the check valve 655 may be omitted. The same applies to the denitration system 6a.

In the reducing agent supply part 63 of the denitration system 6, the circulation flow path 636 may be omitted. In this case, the transfer place of the reducing agent from the reducing agent pump 633 can be switched between the nozzle 61 and the drain pipe by the switching unit 634, so that the reducing agent not supplied to the nozzle 61 is discarded. Furthermore, the switching unit 634 does not necessarily need to be a solenoid valve, but may be a member having another structure (for example, an electric valve driven by a motor or a pilot valve driven by air).

In the control by the supply control unit 72, when the valve closing process of the bypass valve 682 is detected in the middle of the supply of the cleaning liquid from the cleaning liquid supply unit 64, it is not necessary to stop the supply of the cleaning liquid from the detection to the valve closing process After a predetermined time has elapsed, for example, it may be performed immediately after the valve closing process is detected.

In addition, when the supply of the reducing agent to the nozzle 61 is stopped and the cleaning of the nozzle 61 is performed, the supply of the gas from the gas supply unit 65 does not necessarily need to be performed after a predetermined time has elapsed from the supply of the cleaning liquid from the cleaning liquid supply unit 64 For example, it may be performed substantially simultaneously with the supply of the cleaning liquid. In the cleaning of the nozzle 61, it is not necessary to supply the cleaning liquid, and the cleaning of the nozzle 61 may be performed only by the supply of the gas from the gas supply unit 65. In this case, the cleaning liquid supply unit 64 may be omitted. Furthermore, it is not necessary to clean the nozzle 61 after the supply of the reducing agent is stopped. In this case, the cleaning liquid supply unit 64 and the gas supply unit 65 may be omitted.

In the denitration system 6, when the SCR is turned off, the switching unit 634 does not necessarily switch the transporting position of the reducing agent from the nozzle 61 to another configuration. Therefore, the switching unit 634 may not be driven.

In the denitration system 6, as the switching unit 634 shown in FIG. 3, a multi-port valve is provided across the reducing agent piping 632 and the cleaning liquid piping 642, and when the bypass valve 682 is opened, the multi-port valve is switched by The switching position of the reducing agent from the reducing agent pump 633 is switched from the nozzle 61 to the reducing agent supply source 631, and the cleaning liquid from the cleaning liquid pump 643 can be sent to the nozzle 61 via the multi-port valve.

The nozzle 61 does not necessarily need to supply the reducing agent to the exhaust gas collector 422, and only needs to supply the reducing agent to any part of the exhaust gas flow path 42. For example, the nozzle 61 may be attached to the exhaust pipe 421 or the combustion chamber 20 described above, and a reducing agent may be supplied to the exhaust pipe 421 or the combustion chamber 20.

The internal combustion engine 1 and the internal combustion engine 1a need not necessarily include a plurality of combustion chambers 20, and there is no need to provide an exhaust collector 422 in the exhaust flow path 42.

In the internal combustion engine 1 and the internal combustion engine 1a, the supercharger 5 may be omitted. In this case, the reactor 66 and the bypass flow path 681 may be directly connected to the flue 81.

The internal combustion engine 1 and the internal combustion engine 1a do not necessarily need to be the main engine of the ship or the two-stroke diesel engine. The internal combustion engine 1 and the internal combustion engine 1a may be, for example, four-stroke diesel engines or engines other than diesel engines. The internal combustion engine 1 and the internal combustion engine 1a can be used for applications other than the main engine of a ship (for example, an engine such as an automobile). In addition, the internal combustion engine 1 and the internal combustion engine 1a can be used for a generator installed in a machine body of a garbage incineration facility or the like.

The configurations of the above-mentioned embodiment and each modification may be combined as long as they do not contradict each other.

The invention has been depicted and described in detail, but the description is illustrative and not limiting. Therefore, as long as it does not deviate from the scope of the present invention, various modifications and modes can be made.

1, 1a: internal combustion engine 2: cylinder 3: piston 5: Supercharger 6, 6a: Denitration system 20: Combustion chamber 21: cylinder liner 22: cylinder head 23: scavenging port 24: exhaust port 25: exhaust valve 31: Piston head 32: Piston rod 41: Sweep air flow path 42: Exhaust flow path 43: Air cooler 51: Turbo 52: Compressor 61: Nozzle 62: Common piping 63: reducing agent supply unit 64: Cleaning fluid supply unit 65: gas supply unit 66: Reactor 67: SCR flow path 70: control system 71: Inspection Department 72: Supply Control Department 81: flue 82: Inspiratory path 411: scavenge chamber 412: Scavenging collector 421: Exhaust piping 422: exhaust collector 631: Supply of reducing agent 632: reducing agent piping 633: Reductant pump 634: Switching section 635, 645, 655: check valve 636: Circulation flow path 641: Cleaning fluid supply source 642: Cleaning fluid piping 643: Cleaning fluid pump 651: Gas supply source 652: Gas piping 653: Gas supply valve 681: Bypass flow path 682: Bypass valve S11～S20: Step

FIG. 1 is a diagram showing the configuration of the internal combustion engine of the first embodiment. 2 is a diagram showing a part of the configuration of an internal combustion engine. 3 is a diagram showing a part of the configuration of a denitration system. 4 is a diagram showing the configuration of an internal combustion engine. 5 is a diagram showing a part of the configuration of an internal combustion engine. 6 is a diagram showing a part of the configuration of an internal combustion engine. 7 is a diagram showing a flow of stopping supply of a reducing agent. 8 is a diagram showing the configuration of an internal combustion engine. 9 is a diagram showing a part of the configuration of a denitration system of an internal combustion engine in a second embodiment.

1: internal combustion engine

2: cylinder

3: piston

5: Supercharger

6: Denitration system

20: Combustion chamber

21: cylinder liner

22: cylinder head

23: scavenging port

24: exhaust port

25: exhaust valve

31: Piston head

32: Piston rod

41: Sweep air flow path

42: Exhaust flow path

43: Air cooler

51: Turbo

52: Compressor

61: Nozzle

66: Reactor

67: SCR flow path

81: flue

82: Inspiratory path

411: scavenge chamber

412: Scavenging collector

421: Exhaust piping

422: exhaust collector

681: Bypass flow path

682: Bypass valve

Claims (13)

An internal combustion engine, including: Exhaust flow path, for exhaust gas flow; The reducing agent supply unit supplies the reducing agent to the exhaust gas flow path through a nozzle attached to the exhaust gas flow path and mixes with the exhaust gas; The reactor, which makes the exhaust gas flowing from the exhaust gas flow path contact with the catalyst to perform denitration treatment; A flue that guides the exhaust gas passing through the reactor; Bypass the flow path, bypass the reactor and connect the exhaust flow path to the flue; A bypass valve to open and close the bypass flow path; The turbine is disposed between the reactor, the bypass flow path, and the flue, and rotates through exhaust gas; A compressor to pressurize the intake air using the rotation of the turbine as power; and A supply control unit that controls the reducing agent supply unit, The reducing agent supply unit includes: A reducing agent supply source, storing the reducing agent; Piping to connect the reducing agent supply source to the nozzle; and A pump that delivers the reducing agent from the reducing agent supply source to the nozzle via the piping, The supply control unit controls the reducing agent supply unit to stop the supply of the reducing agent to the exhaust gas flow path when the bypass valve opening process or the pump stop process is detected. , With the bypass valve closed, the exhaust gas passing through the reactor flows into the turbine, With the bypass valve open, the exhaust gas passing through the reactor and the bypass flow path flows into the turbine. The internal combustion engine as described in item 1 of the patent application scope, in which The reducing agent supply unit further includes: A switching unit is provided on the piping, and switches the delivery site of the reducing agent delivered by the pump between the nozzle and other configurations than the nozzle, When detecting the valve opening process of the bypass valve or the stop process of the pump, the supply control unit controls the switching unit to switch the delivery position of the reducing agent from the nozzle to the According to the other configuration, the supply of the reducing agent from the nozzle to the exhaust flow path is stopped. The internal combustion engine as described in item 2 of the patent application scope, in which The other configuration is the piping for the reducing agent supply source or the upstream side of the switching unit. The internal combustion engine as described in item 3 of the patent application scope, in which When detecting the valve opening process of the bypass valve, the supply control unit controls the switching unit so as to switch the delivery position of the reducing agent from the nozzle to the other configuration. The internal combustion engine as described in item 4 of the patent application scope, in which The reducing agent supply unit further includes a check valve, and the check valve is provided on the piping near the nozzle between the switching unit and the nozzle. The internal combustion engine as described in item 2 of the patent application scope, in which When detecting the valve opening process of the bypass valve, the supply control unit controls the switching unit so as to switch the delivery position of the reducing agent from the nozzle to the other configuration. The internal combustion engine as described in item 6 of the patent application scope, in which The reducing agent supply unit further includes a check valve, and the check valve is provided on the piping near the nozzle between the switching unit and the nozzle. The internal combustion engine as described in item 2 of the patent application scope, in which The reducing agent supply unit further includes a check valve, and the check valve is provided on the piping near the nozzle between the switching unit and the nozzle. The internal combustion engine as described in any one of items 1 to 8 of the patent application scope, which further includes: A gas supply unit that supplies gas to the nozzle, After stopping the supply of the reducing agent from the nozzle to the exhaust gas flow path, the supply control unit controls the gas supply unit to supply the gas to the nozzle. The internal combustion engine as described in item 9 of the patent application scope further includes: A cleaning liquid supply unit that supplies cleaning liquid to the nozzle, After stopping the supply of the reducing agent from the nozzle to the exhaust gas flow path, the supply control unit controls the cleaning liquid supply unit to supply the cleaning liquid to the nozzle, The supply of the gas from the gas supply unit to the nozzle is started after the supply of the cleaning liquid from the cleaning liquid supply unit to the nozzle is started, and a predetermined time elapses. The internal combustion engine as described in item 10 of the patent application scope, in which The supply control unit, when detecting the valve closing process of the bypass valve in a state where the bypass valve is open, stops supplying the cleaning liquid from the cleaning liquid supply unit to the nozzle after a predetermined time elapses liquid. The internal combustion engine as described in item 1 of the patent application scope, in which When detecting the valve opening process of the bypass valve, the supply control unit stops the operation of the pump, thereby stopping the supply of the reducing agent from the nozzle to the exhaust gas flow path. A control system for controlling the reducing agent supply part in an internal combustion engine including an exhaust gas flow path, a reducing agent supply part, a reactor, a flue bypass flow path, a bypass valve, a turbine, and a compressor, wherein the exhaust gas A flow path for exhaust gas to flow; the reducing agent supply unit supplies a reducing agent to the exhaust gas flow path via a nozzle mounted on the exhaust gas flow path and mixes with the exhaust gas; The exhaust gas flowing into the flow path contacts the catalyst to perform denitration treatment; the flue guides the exhaust gas passing through the reactor; the bypass flow path bypasses the reactor to separate the exhaust gas flow path from The flue connection; the bypass valve opens and closes the bypass flow path; the turbine is disposed between the reactor and the bypass flow path, and the flue, through exhaust Rotation; the compressor uses the rotation of the turbine as power to pressurize the intake air, and in a state where the bypass valve is closed, the exhaust gas passing through the reactor flows into the turbine, at With the bypass valve open, the exhaust gas passing through the reactor and the bypass flow path flows into the turbine, wherein The reducing agent supply unit includes: A reducing agent supply source, storing the reducing agent; Piping to connect the reducing agent supply source to the nozzle; and A pump that delivers the reducing agent from the reducing agent supply source to the nozzle via the piping, The control system includes: A detection unit that detects the valve opening process of the bypass valve or the stop process of the pump; and The supply control unit controls the reducing agent supply unit to stop supply to the exhaust flow path when the detection unit detects the valve opening process of the bypass valve or the stop process of the pump The reducing agent.

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