Engine device

Abstract

To provide an engine device capable of suppressing leakage of emissions containing a toxic substance and thus improving safety without depending on single means when treating the emissions.SOLUTION: An engine device 1 is driven by using fuel containing a toxic substance. The engine device 1 includes an exhaust passage 4 in which emissions exhausted from an engine 2, such as exhaust gas and blow-by gas, are caused to flow, and as devices disposed in the exhaust passage 4 to treat the emissions, includes a plurality of treatment devices having different functions and a path changeover valve 11 disposed in the exhaust passage 4 for switching to a treatment device that treats the emissions out of the plurality of treatment devices. The toxic substance included in the fuel is ammonia or methanol. As the plurality of treatment devices, the engine device 1 includes an exhaust emission control catalyst device 9 and a detoxification device 10.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an engine system that runs on a fuel that contains toxic substances. [Background technology]

[0002] Conventionally, some engine systems are operated by fuels containing toxic substances such as ammonia and methanol, i.e., "harmful substances that should be labeled" under the Industrial Safety and Health Act. Some engine systems are equipped with exhaust purification catalyst devices that purify exhaust gases by catalytic reduction. Specifically, exhaust purification catalyst devices purify exhaust gases by injecting a reducing agent containing toxic substances into the exhaust gases and reducing the toxic substances contained in the exhaust gases to harmless substances, while purifying the toxic substances of the reducing agent that were not used in the reduction (e.g., ammonia that has been slipped) by adsorbing them with a catalyst and decomposing them.

[0003] For example, in Patent Document 1, an exhaust gas purification system for an internal combustion engine configured with a selective catalytic reduction device in an exhaust passage of the internal combustion engine divides a part of the exhaust passage downstream of the selective catalytic reduction device into two branch passages, each of the two branch passages is equipped with an ammonia adsorption and removal device, and a flow path switching device for switching the flow of exhaust gas between the two branch passages is provided at the branch point of the two branch passages. A control device for controlling the exhaust gas purification system controls the flow path switching device to flow exhaust gas into the branch passage equipped with one of the ammonia adsorption and removal devices among the ammonia adsorption and removal devices equipped in each of the two branch passages. In addition, when the detection value of the ammonia concentration detection device becomes equal to or greater than a first set concentration threshold value set in advance, the control device controls the flow path switching device to control the flow of exhaust gas to switch from the branch passage equipped with one ammonia adsorption and removal device to the branch passage equipped with the other ammonia adsorption and removal device. In the conventional technology such as Patent Document 1, an exhaust purification catalyst device is configured by a selective catalytic reduction device and two ammonia adsorption and removal devices. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6743499 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, in the case of an engine device that runs on fuel that does not contain toxic substances, i.e., "harmful substances that should be labeled" under the Industrial Safety and Health Act, an exhaust purification catalyst device that uses a reducing agent that contains toxic substances can adsorb the toxic substances in the slip amount of reducing agent that is not used for reduction with a catalyst, and when an abnormality occurs in the exhaust purification catalyst device, the injection of the reducing agent can be stopped to suppress the emission of toxic substances to the outside. However, in the case of an engine device that runs on fuel that contains toxic substances, since the exhaust gas and blow-by gas emitted from the engine contain toxic substances, in the conventional technology, when an abnormality occurs in the exhaust purification catalyst device, even if the injection of the reducing agent is stopped, the toxic substances contained in the exhaust from the engine are emitted to the outside, which may cause human injury.

[0006] Furthermore, in conventional technology, if exhaust gas remains in the exhaust passage or blow-by gas remains in the crankcase when the engine is stopped, the exhaust purification catalyst device does not operate, making it impossible to ventilate the trapped exhaust gas, blow-by gas, and other exhaust materials, which may result in toxic substances contained in the exhaust materials being discharged to the outside.

[0007] As described above, in the conventional technology, exhaust gas, blow-by gas, and other emissions are treated by a single means, namely a selective catalytic reduction device. If an abnormality occurs in this single means, the function of treating the toxic substances contained in the emissions is impaired, and there is a risk that the toxic substances will leak to the outside, reducing safety.

[0008] An object of the present invention is to provide an engine apparatus capable of suppressing leakage of exhaust matter and improving safety without relying on a single means for treating exhaust matter containing toxic substances. [Means for solving the problem]

[0009] In order to solve the above problems, the engine device of the present invention is an engine device that runs on fuel containing toxic substances, and is characterized in that it comprises an exhaust passage through which exhaust materials discharged from the engine flow, a plurality of treatment devices with different functions that are arranged in the exhaust passage and serve to treat the exhaust materials, and a route switching valve that is arranged in the exhaust passage and switches to one of the plurality of treatment devices that treats the exhaust materials. Effect of the Invention

[0010] According to the present invention, there is provided an engine device capable of suppressing leakage of exhaust material and improving safety without depending on a single means for treating exhaust material containing toxic substances. [Brief description of the drawings]

[0011] [Figure 1] 1 is a schematic diagram illustrating an example of an engine device according to an embodiment of the present invention. [Diagram 2] 4 is a graph showing the relationship between the concentration and mixture ratio of ammonia contained in blow-by gas input / output to / from an exhaust purification catalyst device in an engine device according to an embodiment of the present invention. [Diagram 3] 4 is a table showing an example of a processing device to be used depending on the state of the engine in the engine device according to the embodiment of the present invention. [Figure 4] FIG. 11 is a schematic diagram showing an example of an engine device according to a modified example of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] An engine device 1 according to an embodiment of the present invention will be described with reference to the drawings. As shown in Fig. 1, the engine device 1 includes an engine 2, an intake passage 3, an exhaust passage 4, and a turbocharger 5. Furthermore, the engine device 1 includes a blow-by path 6, a filter 7, an externally driven pump 8, an exhaust purification catalyst device 9, a detoxification device 10, a path switching valve 11, and a control unit 12.

[0013] Particularly in this embodiment, the engine device 1 is an engine that operates by feeding fuel containing toxic substances such as ammonia and methanol, i.e., “harmful substances that should be labeled” under the Industrial Safety and Health Act, into the combustion chamber 21a of the engine 2. The fuel is supplied to the combustion chamber 21a as a mixture with air.

[0014] The engine 2 is, for example, a four-stroke engine, and is configured with a cylinder block 20 including a plurality of cylinders 21 and a crankcase 22. Although six cylinders 21 are illustrated in Fig. 1, the number of cylinders 21 is not limited to six. As shown in Fig. 1, each cylinder 21 is configured with a cylinder 23, a piston 24, and a cylinder head 25.

[0015] The cylinder 23 is formed, for example, in a cylindrical shape within the cylinder block 20, and the piston 24 is slidably housed within the cylinder 23. The cylinder head 25 is attached to the upper side of the cylinder 23, and a combustion chamber 21a is formed inside the cylinder 23 and the cylinder head 25. The cylinder head 25 is provided with an ignition device (not shown) that ignites fuel in the combustion chamber 21a.

[0016] Each cylinder 23 of the multiple cylinders 21 is connected to a crankcase 22, and a crankshaft 26 is rotatably supported by the crankcase 22. A piston 24 of each cylinder 21 is connected to the crankshaft 26 via a connecting rod 27, and the reciprocating motion of the piston 24 is converted into the rotational motion of the crankshaft 26 via the connecting rod 27.

[0017] The cylinder head 25 is connected to the intake passage 3 via an intake port (not shown) and the like, and introduces the air-fuel mixture supplied from the intake passage 3 into the combustion chamber 21a. In addition, the cylinder head 25 is connected to the exhaust passage 4 via an exhaust port (not shown) and the like, and discharges exhaust gas generated in the combustion chamber 21a into the exhaust passage 4.

[0018] 1 illustrates an example in which the intake passage 3 and the multiple cylinders 21 are directly connected, but in order to connect the intake passage 3 and the multiple cylinders 21, an intake manifold having branch passages branching from the intake passage 3 to the multiple cylinders 21 may be provided between the intake passage 3 and the engine 2. Also, in FIG. 1 illustrates an example in which the exhaust passage 4 and the multiple cylinders 21 are directly connected, but in the case of connecting the exhaust passage 4 and the multiple cylinders 21, an exhaust manifold having branch passages branching from the exhaust passage 4 to the multiple cylinders 21 may be provided between the exhaust passage 4 and the engine 2.

[0019] The intake passage 3 is connected to a plurality of cylinders 21 of the engine 2 and supplies compressed and cooled air to each of the cylinders 21. A mixture of air supplied from the intake passage 3 and fuel supplied from a fuel tank (not shown) is supplied from the intake passage 3 to a combustion chamber 21a of each of the cylinders 21. A supercharger 5 is provided upstream in the intake direction of the intake passage 3 for compressing air or a mixture of fuel and air flowing through the intake passage 3 and sending it downstream in the intake direction.

[0020] The intake passage 3 is provided with a fuel supply device (not shown) that supplies fuel to the intake passage 3 on the upstream or downstream side of the turbocharger 5. The intake passage 3 may also be provided with an air filter (not shown) that purifies fresh air and introduces it into the intake passage 3, and an intercooler (not shown) that cools the air flowing through the intake passage 3. The fuel supply device is controlled by the control unit 12 in terms of the amount of fuel supplied (supply pressure) and the supply timing. The fuel supply device may be formed of a venturi mixer that mixes fuel with the air flowing upstream or downstream of the turbocharger 5, or may be formed of an admission valve, an injector, or the like that injects fuel into the intake passage 3 for each of the cylinders 21.

[0021] The exhaust passage 4 distributes exhaust materials discharged from the engine 2, and is mainly connected to a plurality of cylinders 21 of the engine 2, discharging exhaust gas generated in each cylinder 21 as exhaust materials. The exhaust passage 4 is also connected to a blow-by passage 6 connected to a crankcase 22, and discharging blow-by gas circulated through the blow-by passage 6 as exhaust materials.

[0022] The exhaust passage 4 is connected downstream in the exhaust direction to a plurality of treatment devices having different functions for treating exhaust gas, blow-by gas, and other emissions flowing through the exhaust passage 4. In this embodiment, an exhaust purification catalyst device 9 and a detoxification device 10 are applied as the plurality of treatment devices. The exhaust passage 4 has a plurality of branch paths 6a and 6b that branch off downstream in the exhaust direction from the turbine 5a of the turbocharger 5 and head toward the plurality of treatment devices. The branch path 6a is provided with the exhaust purification catalyst device 9 as a treatment device, and the branch path 6b is provided with the detoxification device 10 as a treatment device.

[0023] A path switching valve 11 is provided at a branch point where the exhaust passage 4 branches into the multiple branch paths 6a and 6b. The path switching valve 11 is controlled by a control unit 12 to switch the path so that the exhaust gas flowing through the exhaust passage 4 flows to either of the multiple branch paths 6a and 6b.

[0024] The turbocharger 5 compresses the air or air-fuel mixture flowing through the intake passage 3 and sends it downstream in the intake direction. The turbocharger 5 has a turbine 5a and a compressor 5b. The turbine 5a is disposed in the exhaust passage 4, and the compressor 5b is disposed in the intake passage 3. The turbine 5a is rotated by the exhaust gas flowing through the exhaust passage 4, and the compressor 5b is driven by the rotational force of the turbine 5a, thereby compressing the air or air-fuel mixture flowing through the intake passage 3.

[0025] The blow-by path 6 is connected from the crankcase 22 to the exhaust passage 4. The blow-by path 6 is connected to the exhaust passage 4 upstream of the path switching valve 11 in the exhaust direction in the exhaust passage 4. Although FIG. 1 illustrates an example in which the blow-by path 6 and the exhaust passage 4 are directly connected, a valve such as a check valve that prevents exhaust gas from flowing into the blow-by path 6 may be provided between the blow-by path 6 and the exhaust passage 4. While fuel gas leaks from the combustion chamber 21a of each cylinder 21 into the crankcase 22, generating blow-by gas in the crankcase 22, the blow-by gas flows through the blow-by path 6.

[0026] The filter 7 is provided upstream in the flow direction of the blow-by gas in the blow-by path 6. The filter 7 separates oil mist contained in the blow-by gas flowing through the blow-by path 6 to produce an unburned air-fuel mixture, and is constituted by, for example, a mist separator.

[0027] The externally driven pump 8 is provided in the blow-by path 6 downstream of the filter 7 in the blow-by gas flow direction. The externally driven pump 8 is driven regardless of whether the engine 2 is running (operating) or not, and causes the blow-by gas to flow in the blow-by path 6 communicated with the crankcase 22, thereby ventilating the crankcase 22 and creating a negative pressure in the crankcase 22. This prevents the blow-by gas in the crankcase 22 from leaking from the crankcase 22 at a location other than the blow-by path 6, for example, preventing the blow-by gas from leaking from the crankcase 22 at a pivotal support location of the crankshaft 26. That is, the externally driven pump 8 functions as a treatment device that treats the blow-by gas in the crankcase 22.

[0028] The externally driven pump 8 may be driven at the same intensity regardless of whether the engine 2 is running (operating) or not, and may cause the blow-by gas to flow at the same intensity. Alternatively, the externally driven pump 8 may be driven at a relatively high intensity when the engine 2 is operating, and driven at a relatively low intensity when the engine 2 is stopped. Alternatively, the externally driven pump 8 may be driven until a predetermined time has elapsed after the engine 2 is stopped, and may be stopped after the predetermined time has elapsed.

[0029] The exhaust purification catalyst device 9 is disposed in the branch path 6a of the exhaust passage 4, downstream of the path switching valve 11 in the exhaust direction. The exhaust purification catalyst device 9 purifies emissions such as exhaust gas and blow-by gas flowing through the branch path 6a by catalytic reduction using a reducing agent such as urea water. The branch path 6a discharges the emissions purified by the exhaust purification catalyst device 9. The exhaust purification catalyst device 9 operates in response to the operation of the engine 2, and is activated by warming up the catalyst.

[0030] For example, Fig. 2 shows the relationship between the concentration and mixture ratio of ammonia contained in the exhaust gases input and output to the exhaust catalytic device 9. In Fig. 2, the exhaust gases input to the exhaust catalytic device 9 are plotted as white circles, and the exhaust gases output from the exhaust catalytic device 9 are plotted as black circles. As shown in Fig. 2, the concentration of ammonia output can be sufficiently suppressed by the exhaust catalytic device 9, regardless of the mixture ratio of ammonia.

[0031] The abatement device 10 is disposed in the branch path 6b of the exhaust passage 4 downstream of the path switching valve 11 in the exhaust direction. The abatement device 10 operates regardless of whether the engine 2 is running (operating) or not, and renders the exhaust harmless by removing target substances (toxic substances such as ammonia and methanol) contained in the exhaust gas, blow-by gas, and other exhaust gases flowing through the branch path 6b. The branch path 6b discharges the exhaust gases rendered harmless by the abatement device 10. The abatement device 10 is configured, for example, as a gas decomposition type abatement device, a scrubber type abatement device, a combustion abatement type abatement device, or a catalytic decomposition type abatement device.

[0032] Gas decomposition abatement equipment is a device that uses decomposition elements to electrically and chemically decompose target substances (toxic substances) in emissions to remove them. Gas decomposition abatement equipment consumes relatively little power and can be constructed with relatively inexpensive equipment, but requires a neutralizing agent. Scrubber abatement equipment is a device that utilizes the solubility of target substances (toxic substances) in water and specific chemical solutions to remove the target substances by spraying cleaning solutions such as water and sulfuric acid onto the emissions. Scrubber abatement equipment can be constructed with relatively inexpensive equipment, but the equipment size is large.

[0033] In addition, the combustion abatement type abatement device is a device that decomposes and abats target substances (toxic substances) by burning the exhaust with a burner or the like to heat it up. The combustion abatement type abatement device is suitable for abating high concentrations of target substances, but it consumes a lot of power, incurs fuel costs, and is large in equipment size. The catalytic decomposition type abatement device is a device that abats target substances at low temperatures by utilizing a catalyst that promotes the reduction and decomposition of target substances (toxic substances) contained in the exhaust. The catalytic decomposition type abatement device can abatement target substances at relatively low temperatures, but the equipment size is large, the equipment is expensive, and the running costs increase. In the engine system 1, an appropriate abatement device 10 is applied after taking into consideration the advantages and disadvantages as described above.

[0034] The control unit 12 is a computer such as an ECU (Engine Control Unit) that controls the operation of the engine 2, and includes a CPU, ROM, RAM, etc., and is configured to control each part of the engine 2. The control unit 12 may store various programs for controlling the engine 2, and control the engine 2 by reading and executing the programs.

[0035] In particular, the control unit 12 controls the path switching valve 11 according to the state of the engine 2 and the plurality of treatment devices to switch to one of the plurality of branch paths 6a and 6b, thereby switching the treatment device that performs the treatment of the exhaust material among the plurality of treatment devices. Fig. 3 shows an example of the treatment device that is used according to the state of the engine 2. In Fig. 3, the treatment device that is used as the main treatment device is shown by a black circle, and the treatment device that is used as a backup in case of a malfunction of the main treatment device is shown by a white circle.

[0036] Specifically, the control unit 12 monitors whether the engine 2 is operating or stopped. When the engine 2 is operating, the control unit 12 normally controls the exhaust gas purification catalyst device 9 to treat the exhaust gas, i.e., switches the exhaust gas route to the branch route 6a by the route switching valve 11.

[0037] On the other hand, even when the engine 2 is in operation, if an abnormality occurs in the treatment of emissions by the exhaust gas purification catalyst device 9, the control unit 12 controls the treatment of emissions to be switched from the exhaust gas purification catalyst device 9 to the abatement device 10, that is, switches the route of the emissions to the branch route 6b by the route switching valve 11. In other words, while the engine 2 is in operation, the control unit 12 mainly uses the exhaust gas purification catalyst device 9, and uses the abatement device 10 as a backup depending on the state of the engine 2 and the multiple treatment devices.

[0038] For example, in order to determine whether or not an abnormality has occurred in the treatment of emissions by the exhaust catalytic device 9, the control unit 12 may monitor whether or not the exhaust catalytic device 9 is operating in conjunction with the operation of the engine 2, and determine that an abnormality has occurred in the treatment of emissions when the exhaust catalytic device 9 is not operating. Alternatively, the engine device 1 may be provided with a sensor that detects harmful substances such as ammonia and methanol contained in the exhaust gas from the exhaust catalytic device 9. Then, based on the detection result of the sensor, the control unit 12 may determine that an abnormality has occurred in the treatment of emissions when harmful substances equal to or greater than a predetermined threshold value are detected.

[0039] In addition, even when the engine 2 is operating, if the exhaust gas purification catalyst device 9 is not sufficiently treating the exhaust gas, the control unit 12 controls the treatment of the exhaust gas to be switched from the exhaust gas purification catalyst device 9 to the decontamination device 10, i.e., the path switching valve 11 switches the path of the exhaust gas to the branch path 6b.

[0040] For example, in order to determine whether or not the treatment of emissions by the exhaust purification catalytic device 9 is sufficient, the engine device 1 is provided with a torque sensor that detects the load (torque) of the engine 2 and a temperature sensor that detects the temperature of the exhaust gas flowing through the exhaust passage 4. Then, based on the detection results of the torque sensor and the temperature sensor, the control unit 12 may determine that the treatment of emissions is insufficient when it detects a decrease in the exhaust gas temperature (e.g., a decrease below a predetermined temperature threshold) associated with a decrease in the load of the engine 2 (e.g., a decrease below a predetermined torque threshold).

[0041] Furthermore, when the engine 2 is stopped, the control unit 12 controls the processing of exhaust gases to be switched from the exhaust gas purification catalyst device 9 to the abatement device 10, that is, the path of the exhaust gases is switched to the branch path 6b by the path switching valve 11. In other words, after the engine 2 is stopped, the control unit 12 mainly uses the exhaust gas purification catalyst device 9, and uses the abatement device 10 as a backup depending on the state of the engine 2 and the multiple treatment devices.

[0042] In addition, when the engine 2 is stopped in an emergency, the control unit 12 preferably uses the abatement device 10 as the main device, and uses the exhaust purification catalyst device 9 as a backup device depending on the state of the engine 2 and the multiple treatment devices.

[0043] As described above, according to this embodiment, the engine device 1 is an engine device 1 that runs on a fuel containing toxic substances, and includes an exhaust passage 4 through which exhaust gas, blow-by gas, and other emissions discharged from an engine 2 flow, a plurality of treatment devices (exhaust purification catalyst device 9 and abatement device 10) with different functions as devices disposed in the exhaust passage 4 for treating the emissions, and a path switching valve 11 disposed in the exhaust passage 4 for switching to a treatment device that performs treatment of the emissions among the plurality of treatment devices. The abatement device 10 of the treatment device is a gas decomposition type abatement device, a scrubber type abatement device, a combustion abatement type abatement device, or a catalytic decomposition type abatement device. The toxic substances contained in the fuel are ammonia or methanol.

[0044] As a result, even if an abnormality occurs in one of the processing devices for processing the exhaust, that is, even if a single abnormality occurs, the engine device 1 can process the exhaust by switching to another processing device. Therefore, the processing of the exhaust containing toxic substances does not depend on a single means, and even if a single abnormality occurs, it is possible to prevent the toxic substances contained in the exhaust from leaking to the outside, thereby contributing to improved safety. In addition, since the intake passage 3 is not used for processing the exhaust, it is possible to suppress the intake system components such as the intake passage 3 and the compressor 5b of the turbocharger 5 from being contaminated by the exhaust, and the replacement interval of the intake system components can be extended. In addition, since the intake system components can be configured without adopting corrosion-resistant members or corrosion-resistant coatings against the exhaust, it is possible to suppress an increase in the cost of the intake system components and a decrease in the marketability of the intake system components.

[0045] Furthermore, according to this embodiment, the engine device 1 is provided with a blow-by path 6 that is connected from the crankcase 22 to the exhaust passage 4 upstream of the path switching valve 11 in the exhaust direction, and an externally driven pump 8 that causes the blow-by gas generated in the crankcase 22 to flow through the blow-by path 6.

[0046] As a result, even when the engine 2 stops operating, the engine device 1 ventilates the crankcase 22 by the externally driven pump 8 and creates a negative pressure in the crankcase 22. Therefore, even when the engine 2 is stopped, the toxic substances in the blow-by gas remaining in the crankcase 22 can be detoxified, the risk of contamination of the surrounding environment can be reduced, and safety can be improved. In addition, since the blow-by path 6 is connected to the exhaust passage 4, the treatment device can treat not only the exhaust gas from the engine 2 but also the blow-by gas from the crankcase 22.

[0047] More specifically, according to this embodiment, the engine device 1 includes an exhaust gas purification catalyst device 9 and a detoxification device 10 as a plurality of treatment devices.

[0048] As a result, the engine system 1 can treat the blow-by gas by selectively switching between the exhaust purification catalytic device 9 and the abatement device 10 as appropriate according to the state of the engine 2 and each treatment device.

[0049] Furthermore, according to this embodiment, during engine operation, the engine device 1 normally processes emissions using the exhaust purification catalyst device 9, but if an abnormality occurs in the processing of emissions by the exhaust purification catalyst device 9, the processing of emissions is switched from the exhaust purification catalyst device 9 to the decontamination device 10.

[0050] As a result, even if an abnormality occurs in the exhaust purification catalytic device 9, the engine device 1 can smoothly treat the exhaust gas by the abatement device 10.

[0051] Alternatively, according to this embodiment, during engine operation, the engine device 1 normally treats emissions using the exhaust purification catalyst device 9, but when the treatment of emissions by the exhaust purification catalyst device 9 is insufficient, the treatment of emissions is switched from the exhaust purification catalyst device 9 to the decontamination device 10.

[0052] As a result, even if the exhaust purification catalyst device 9 is unable to sufficiently treat the emissions due to a change or abnormality in the engine operating condition other than that of the exhaust purification catalyst device 9, such as a decrease in the load on the engine 2 or a drop in the exhaust gas temperature, the engine device 1 can smoothly treat the emissions using the decontamination device 10.

[0053] Alternatively, according to this embodiment, the engine device 1 treats exhaust emissions using the exhaust purification catalyst device 9 while the engine 2 is operating, and when the engine 2 is stopped, the treatment of exhaust emissions is switched from the exhaust purification catalyst device 9 to the abatement device 10.

[0054] As a result, even if the engine 2 is stopped and the exhaust gas purification catalytic device 9 is unable to treat the exhaust gas, the engine device 1 can smoothly treat the exhaust gas by the abatement device 10.

[0055] In the above embodiment, the engine device 1 connects the blow-by passage 6 to the exhaust passage 4 in order to switch the blow-by gas as an exhaust gas to the exhaust catalytic converter 9 or the abatement device 10 for processing, but the present invention is not limited to this example. For example, in a modified example, the engine device 1 may be configured without the blow-by passage 6 connected to the exhaust passage 4, as shown in FIG. 4, so that only the exhaust gas as an exhaust gas is switched to the exhaust catalytic converter 9 or the abatement device 10 for processing. In FIG. 4, an example in which the engine device 1 does not include the blow-by passage 6 is illustrated, but in another example, the engine device 1 may include the blow-by passage 6 connected to another processing device instead of the exhaust passage 4.

[0056] In addition, the present invention can be modified as appropriate within the scope that does not contradict the gist or concept of the invention that can be read from the claims and the entire specification, and engine devices involving such modifications are also included in the technical concept of the present invention.

[0057] [Appendix to the invention] The following will provide an overview of the invention extracted from the above-described embodiment. Note that the configurations and processing functions described in the following supplementary notes can be selected and combined as desired.

[0058] <Appendix 1> An engine device that runs on a fuel containing a toxic substance, an exhaust passage through which exhaust gas discharged from the engine flows; a plurality of treatment devices having different functions, each of which is disposed in the exhaust passage and serves to treat the exhaust; an exhaust passage for switching to a treatment device that performs treatment of the exhaust gas from among the plurality of treatment devices;

[0059] <Appendix 2> a blow-by path connected to the exhaust passage upstream of the path switching valve in an exhaust direction; 2. The engine device according to claim 1, further comprising: an externally driven pump that causes blow-by gas to flow through the blow-by path.

[0060] <Appendix 3> 3. The engine system according to claim 1 or 2, wherein the plurality of treatment devices include an exhaust gas purification catalyst device and a detoxification device.

[0061] <Appendix 4> 4. The engine device according to claim 3, characterized in that, when an abnormality occurs in the treatment of the exhaust by the exhaust purification catalyst device during engine operation, the treatment of the exhaust is switched from the exhaust purification catalyst device to the abatement device.

[0062] <Appendix 5> 5. The engine system according to claim 3 or 4, characterized in that, when the treatment of the exhaust gas by the exhaust gas purification catalyst device is not sufficient during engine operation, the treatment of the exhaust gas is switched from the exhaust gas purification catalyst device to the abatement device.

[0063] <Appendix 6> The engine device according to any one of claims 3 to 5, characterized in that while the engine is operating, the exhaust gas purification catalyst device treats the exhaust gas, and when the engine is stopped, the exhaust gas purification catalyst device treats the exhaust gas, and the treatment of the exhaust gas is switched from the exhaust gas purification catalyst device to the abatement device.

[0064] <Appendix 7> 7. The engine system according to any one of claims 3 to 6, wherein the abatement device is a gas decomposition type abatement device, a scrubber type abatement device, a combustion abatement type abatement device, or a catalytic decomposition type abatement device.

[0065] <Appendix 8> 8. The engine device according to claim 1, wherein the toxic substance is ammonia or methanol. [Explanation of symbols]

[0066] 1 Engine unit 2 Engine 3 Intake passage 4 Exhaust passage 5. Turbocharger 5a Turbine 5b Compressor 6 Blow-by path 6a, 6b, 6c Branching Path 7 Filters 8 Externally driven pump 9. Exhaust gas purification catalyst device 10 Abatement equipment 11. Path switching valve 12 Control unit 20 Cylinder block 21 cylinders 21a Combustion chamber 22 Crankcase 23 Cylinder 24 Piston 25 Cylinder head 26 Crankshaft 27 Connecting rod

Claims

1. An engine device that runs on a fuel containing a toxic substance, an exhaust passage through which exhaust gas discharged from the engine flows; a plurality of treatment devices having different functions, each of which is disposed in the exhaust passage and serves to treat the exhaust; an exhaust passage for switching to a treatment device that performs treatment of the exhaust gas from among the plurality of treatment devices;

2. a blow-by path connected to the exhaust passage upstream of the path switching valve in an exhaust direction; 2. The engine system according to claim 1, further comprising: an externally driven pump for causing blow-by gas to flow through the blow-by passage.

3. 2. The engine system according to claim 1, wherein the plurality of treatment devices include an exhaust gas purification catalyst device and an abatement device.

4. 4. The engine system according to claim 3, wherein, when an abnormality occurs in the treatment of the exhaust gas by the exhaust gas purification catalyst device during engine operation, the treatment of the exhaust gas is switched from the exhaust gas purification catalyst device to the abatement device.

5. 4. The engine system according to claim 3, wherein, when the treatment of the exhaust gas by the exhaust gas purification catalyst device is not sufficient during engine operation, the treatment of the exhaust gas is switched from the exhaust gas purification catalyst device to the abatement device.

6. 4. The engine system according to claim 3, wherein the exhaust gas is treated by the exhaust gas purification catalyst device while the engine is in operation, and the treatment of the exhaust gas is switched from the exhaust gas purification catalyst device to the abatement device when the engine is stopped.

7. 4. The engine system according to claim 3, wherein the abatement device is a gas decomposition type abatement device, a scrubber type abatement device, a combustion abatement type abatement device, or a catalytic decomposition type abatement device.

8. 2. The engine apparatus according to claim 1, wherein the toxic substance is ammonia or methanol.

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