Exhaust emission control device

Abstract

To provide an exhaust emission control system and an exhaust emission control device that efficiently eliminate poisoning components to purify an exhaust gas.SOLUTION: An exhaust emission control system 1 applied to a gas consumption device 2 that consumes a fuel gas and discharges an exhaust gas includes: a desulfurizer 5 provided in an exhaust passage 4 for discharging the exhaust gas from the gas consumption device 2 and accommodating a desulfurizing agent for removing poisoning components included in the exhaust gas; an oxidation treatment device 6 that is provided in the exhaust passage 4 downstream of the desulfurizer 5 in an exhaust gas discharge direction to be adjacent to or come in contact with the desulfurizer 5 and accommodates an oxidation catalyst for oxidizing harmful components included in the exhaust gas; and a control unit 130 that is a control section for controlling the gas consumption device 2 so that the fuel gas supplied to at least one cylinder 110 out of a plurality of cylinders 110 provided in the gas consumption device 2 is discharged to the exhaust passage 4 during regeneration of the desulfurizer 5.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an exhaust gas purification device that includes a desulfurizer and an oxidation catalyst and purifies exhaust gas from a gas consuming device such as an engine that consumes fuel gas. [Background technology]

[0002] An exhaust gas purification system or an exhaust gas purification device is applied to a gas consuming device such as an engine that consumes a fuel gas such as natural gas. The exhaust gas purification system or the exhaust gas purification device is equipped with a desulfurizer that adsorbs and removes poisonous components such as sulfur compounds, and an oxidation catalyst that oxidizes and removes harmful components such as hydrocarbons, and purifies the exhaust gas discharged from the gas consuming device.

[0003] For example, the exhaust gas purification device disclosed in Patent Document 1 includes a gas consumption device that consumes fuel gas containing hydrocarbons and sulfur compounds, a desulfurizer into which exhaust gas discharged from the gas consumption device is introduced and which contains a desulfurizing agent that adsorbs the sulfur compounds in the exhaust gas, a heating means for heating the desulfurizing agent, and an oxidation treatment device into which desulfurized exhaust gas discharged from the desulfurizer is introduced and which contains a catalyst that oxidizes the hydrocarbons and carbon monoxide in the desulfurized exhaust gas. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2018-135808 A Summary of the Invention [Problem to be solved by the invention]

[0005] When a certain amount of sulfur compounds is adsorbed on the desulfurizer, the desulfurizer's ability to remove sulfur compounds decreases, and therefore the desulfurizer must be regenerated by heating the desulfurizer to desorb the sulfur compounds. When the desulfurizer is disposed upstream of the oxidation catalyst in the exhaust direction of the exhaust gas, as in conventional exhaust gas purification devices, the desulfurizer must be regenerated by supplying fuel gas to the oxidation catalyst and feeding back the heat generated by the oxidation process of the fuel gas to the upstream desulfurizer, which makes the configuration complicated. In addition, there is a risk that the sulfur compounds desorbed during the regeneration of the desulfurizer will flow to the oxidation catalyst, deteriorating the oxidation catalyst.

[0006] Furthermore, when the desulfurizer is disposed downstream of the gas consumption device in the exhaust direction of the exhaust gas as in the conventional exhaust gas purification device, the high-temperature exhaust gas flows through the desulfurizer. Since the desulfurizer has difficulty in adsorbing the sulfur compounds contained in the high-temperature exhaust gas, the efficiency of removing the sulfur compounds may decrease. In addition, since it is necessary to provide a desulfurizing agent that can withstand high temperatures, the cost of the desulfurizer itself may increase. Furthermore, since it is necessary to heat the desulfurizing agent to a higher temperature, for example, to 500 degrees or higher in order to regenerate such a desulfurizing agent, the cost of the heating means such as a heater or burner for heating the desulfurizer increases, and the configuration may become complicated due to the installation of the heating means.

[0007] In addition, the exhaust gas purification device of Patent Document 1 is provided with a bypass between an airway that supplies fuel gas to the gas consumption device and an airway that discharges exhaust gas from the gas consumption device, which is short-circuited to avoid the gas consumption device. When the fuel gas is introduced into the oxidation treatment device by the bypass, oxidation reaction heat of the fuel gas is generated, and this oxidation reaction heat is transferred to the desulfurizer to regenerate the desulfurizer. Alternatively, the exhaust gas purification device of Patent Document 1 heats the desulfurizer with a heating means such as a heater or a burner to regenerate it. However, when the exhaust gas purification device is provided with a bypass or a heating means such as a heater or a burner, there is a risk that the cost will be high and the configuration will be complicated. In addition, there is a risk that the sulfur compounds desorbed during regeneration of the desulfurizer will flow to the oxidation catalyst, causing the oxidation catalyst to deteriorate.

[0008] As a result of the above, in the conventional exhaust gas purification device, the efficiency of purifying exhaust gas is reduced due to the complicated configuration and the deterioration of fuel efficiency.

[0009] An object of the present invention is to provide an exhaust gas purification system and an exhaust gas purification device that efficiently remove poisonous components to purify exhaust gas. [Means for solving the problem]

[0010] In order to solve the above problems, the exhaust gas purification device of the present invention is an exhaust gas purification device applied to a gas consumption device that consumes fuel gas and emits exhaust gas, and is characterized in that it comprises a desulfurizer that is provided in an exhaust path that discharges the exhaust gas from the gas consumption device and contains a desulfurizing agent that removes poisonous components contained in the exhaust gas, an oxidation treatment device that is provided in the exhaust path downstream of the desulfurizer in close proximity to or in contact with the desulfurizer in the exhaust direction of the exhaust gas and contains an oxidation catalyst that oxidizes harmful components contained in the exhaust gas, and a control unit that controls the gas consumption device so that the fuel gas supplied to at least one of the multiple cylinders provided in the gas consumption device is discharged into the exhaust path when the desulfurizer is regenerated. Effect of the Invention

[0011] According to the present invention, there are provided an exhaust gas purification system and an exhaust gas purification device that efficiently remove poisonous components to purify exhaust gas. [Brief description of the drawings]

[0012] [Figure 1] 1 is a schematic diagram showing an exhaust gas purification system according to a first embodiment of the present invention. [Diagram 2] 3 is a flowchart showing the operation of the exhaust gas purification system according to the first embodiment of the present invention. [Diagram 3] FIG. 4 is a schematic diagram showing an exhaust gas purification device according to a second embodiment of the present invention. [Figure 4] FIG. 5 is a schematic diagram showing a gas consumption device that is applied to an exhaust gas purification device according to a second embodiment of the present invention. [Diagram 5] 5 is a flowchart showing the operation of the exhaust gas purification system according to the second embodiment of the present invention. [Figure 6] FIG. 11 is a schematic diagram showing an exhaust gas purification device in a normal mode according to a third embodiment of the present invention. [Figure 7] FIG. 11 is a schematic diagram showing an exhaust gas purification device in a regeneration mode according to a third embodiment of the present invention. [Figure 8] FIG. 11 is a schematic diagram showing an exhaust gas purification device in a normal mode according to a fourth embodiment of the present invention. [Figure 9] FIG. 11 is a schematic diagram showing an exhaust gas purification device in a regeneration mode according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] An exhaust gas purification system 1 according to a first embodiment of the present invention will be described. As shown in Fig. 1, the exhaust gas purification system 1 is applied to a gas consumption device 2 such as an engine that consumes fuel gas such as natural gas, and purifies exhaust gas discharged from the gas consumption device 2. Since fuel gas contains harmful components such as hydrocarbons that cause air pollution and poisoning components such as sulfur compounds that cause catalyst deterioration, the exhaust gas purification system 1 is configured to remove these harmful components and poisoning components.

[0014] The gas consumption device 2 is connected to a supply path 3 that supplies fuel gas from a fuel tank or the like, and an exhaust path 4 that discharges exhaust gas. The exhaust gas purification system 1 includes a desulfurizer 5 that removes poisonous components such as sulfur compounds contained in the fuel gas, and an oxidation treatment device 6 that oxidizes harmful components such as hydrocarbons contained in the exhaust gas. The exhaust gas purification system 1 is also configured to include the above-mentioned exhaust path 4, and includes a bypass path 7 branching off from the exhaust path 4. The exhaust gas purification system 1 includes a switching unit 8 at the branch position between the exhaust path 4 and the bypass path 7, and further includes a heat exchanger 9 in the bypass path 7.

[0015] The gas consumption device 2 is composed of an engine that burns and operates using a fuel gas such as liquefied natural gas (LNG). These engines include gas engines that use a fuel gas as fuel, dual fuel engines that operate using a fuel gas and a liquid fuel such as gasoline or diesel fuel, and bi-fuel engines that switch between operation using a fuel gas and operation using a liquid fuel. These engines are applied, for example, to driving sources for ships such as coastal ships, and driving sources for land use such as generators and heat pumps. For example, the gas consumption device 2 includes a plurality of cylinders 10, an intake section 11, a fuel gas supply section 12, and an exhaust section 13, and each cylinder 10 houses a piston (not shown).

[0016] The intake section 11 includes an intake manifold 15 connected to the combustion chamber of each cylinder 10. The intake manifold 15 includes distribution paths 16 connected to the combustion chamber of each cylinder 10, and distributes air supplied from an intake pipe (not shown) and supplies it to the combustion chamber of each cylinder 10.

[0017] The fuel gas supply unit 12 is connected to the supply path 3, and distributes and supplies fuel gas supplied from a fuel tank (not shown) or the like via the supply path 3 to the combustion chambers of each cylinder 10. For example, the fuel gas supply unit 12 distributes the fuel gas to each distribution path 16 of the intake manifold 15 of the intake unit 11.

[0018] As a result, a mixture of air supplied from the intake pipe and fuel gas supplied from the fuel gas supply unit 12 is supplied to the combustion chamber of each cylinder 10 via each distribution path 16 of the intake manifold 15. Each distribution path 16 is provided with a throttle valve (not shown), and the ratio and amount of the mixture gas supplied to the combustion chamber of each cylinder 10 is adjusted by the throttle valve.

[0019] The exhaust section 13 includes an exhaust manifold 17 connected to the combustion chambers of each cylinder 10. The exhaust manifold 17 is also connected to the exhaust path 4, and collects exhaust gas discharged from the combustion chambers of each cylinder 10 and discharges it through the exhaust path 4.

[0020] The desulfurizer 5 is provided in the supply path 3 between the fuel tank and the fuel gas supply unit 12 of the gas consumption device 2, in other words, upstream of the gas consumption device 2 in the fuel gas supply direction, so that the fuel gas flowing through the supply path 3 passes through the desulfurizer 5. The desulfurizer 5 contains a desulfurizing agent that removes poisoning components such as sulfur compounds from the fuel gas. For example, the desulfurizer 5 has an adsorbent such as activated carbon or zeolite that physically adsorbs the poisoning components as a desulfurizing agent, or has a chemical adsorption desulfurizing agent made of a direct decomposition type hydrogen sulfide production catalyst and a catalyst containing zirconium oxide and zinc oxide that removes the poisoning components.

[0021] The desulfurizer 5 removes poisonous components from the fuel gas flowing through the supply path 3 by adsorbing them to a desulfurizing agent, and poisonous substances consisting of the poisonous components are accumulated in the desulfurizing agent. As a result, the fuel gas from which the poisonous components have been removed, i.e., the desulfurized fuel gas, is supplied to the gas consumption device 2.

[0022] When the desulfurizing agent is heated to a predetermined regeneration temperature or higher, poisonous substances such as sulfur compounds adsorbed to the desulfurizing agent are desorbed, and the desulfurizer 5 is regenerated. The desulfurizing agent made of activated carbon, zeolite, or the like is a catalyst that can be regenerated at a relatively low temperature, for example, at about 200 degrees. In addition, the exhaust gas purification system 1 may include a temperature sensor 18 near the desulfurizer 5 for detecting the temperature of the desulfurizer 5.

[0023] The oxidation processor 6 is provided in the exhaust path 4 so that the exhaust gas flowing through the exhaust path 4 passes through the oxidation processor 6. The oxidation processor 6 contains an oxidation catalyst that removes harmful components such as hydrocarbons (e.g., methane) and carbon monoxide from the exhaust gas. The oxidation processor 6 removes the harmful components by oxidizing them to carbon dioxide and water using the oxidation catalyst.

[0024] The bypass path 7 branches off from the exhaust path 4 between the exhaust unit 13 of the gas consumption device 2 and the oxidation treatment device 6, in other words, upstream of the oxidation treatment device 6 in the exhaust direction of the exhaust gas. As a result, the exhaust of exhaust gas from the gas consumption device 2 via the exhaust path 4 is divided into exhaust via the oxidation treatment device 6 and exhaust via the bypass path 7.

[0025] As described above, the switching unit 8 is provided at the branching position to the bypass path 7 in the exhaust path 4. The switching unit 8 is configured to switch the exhaust of exhaust gas from the gas consumption device 2 through the exhaust path 4 between the exhaust via the oxidation treatment device 6 and the bypass path 7. In other words, the switching unit 8 is configured with a damper, a valve, or the like that switches the flow path downstream of the branching position in the exhaust direction of the exhaust gas between the flow path on the oxidation treatment device 6 side and the flow path on the bypass path 7 side. The switching unit 8 fully closes either the flow path on the oxidation treatment device 6 side or the flow path on the bypass path 7 side. For example, the switching unit 8 is controlled to switch to the flow path on the bypass path 7 side during regeneration of the desulfurizer 5.

[0026] As described above, the heat exchanger 9 is provided in the bypass passage 7, and is disposed in the vicinity of or in contact with the desulfurizer 5. When the exhaust gas flows through the bypass passage 7, the heat exchanger 9 performs a heating process by heat exchange using the high-temperature exhaust gas to heat the desulfurizer 5. Note that the heat exchanger 9 may heat a heat transfer material, and heat the desulfurizer 5 through the heat transfer material.

[0027] The exhaust gas purification system 1 also includes a control unit 20. The control unit 20 is configured to include a computer such as a CPU, and a storage device including a ROM, a RAM, and the like. The storage device stores programs and data for controlling the various components and functions of the exhaust gas purification system 1, and the computer controls the various components and functions by executing arithmetic processing based on the programs and data stored in the storage device. The control unit 20 may be configured by utilizing an engine ECU that controls an engine, which is the gas consumption device 2.

[0028] The exhaust gas purification system 1 operates by switching between a normal mode and a regeneration mode as an operation mode. The control unit 20 functions as a mode control unit 21 that controls the operation mode by executing a program stored in a storage device.

[0029] The mode control unit 21 switches the operation mode to the normal mode when the gas consumption device 2 is operated normally, and switches the operation mode to the regeneration mode when regenerating the desulfurizer 5. In addition, the mode control unit 21 stops the heat exchanger 9 in the normal mode, and operates the heat exchanger 9 in the regeneration mode.

[0030] For example, the mode control unit 21 usually sets the operation mode to the normal mode, and when the accumulated amount of poisoning substances accumulated in the desulfurizer 5 exceeds a predetermined accumulated amount threshold, the mode control unit 21 switches the operation mode from the normal mode to the regeneration mode. The accumulated amount threshold is appropriately set according to the type of desulfurization material of the desulfurizer 5.

[0031] The mode control unit 21 detects the amount of fuel gas supplied to the gas consumption device 2 or the amount of exhaust gas discharged from the gas consumption device 2, and estimates and calculates the accumulated amount of poisoning substances based on the amount of fuel gas supplied or the amount of exhaust gas discharged. For example, the mode control unit 21 may detect the amount of fuel gas supplied by a fuel gas flow sensor 22 provided in the supply path 3. The mode control unit 21 may also detect the amount of exhaust gas supplied by an exhaust gas flow sensor 23 provided in the exhaust path 4. The mode control unit 21 resets the accumulated amount of poisoning substances when switching the operation mode from the regeneration mode to the normal mode.

[0032] Alternatively, the mode control unit 21 may switch the operation mode to the regeneration mode when another abnormality in the desulfurizer 5 is detected or when regeneration of the desulfurizer 5 is instructed by manual operation.

[0033] After the regeneration of the desulfurizer 5 is completed in the regeneration mode, for example, after a predetermined regeneration time has elapsed since the regeneration of the desulfurizer 5 was started, the mode control unit 21 switches the operation mode from the regeneration mode to the normal mode.

[0034] Next, an operation example of the normal mode of the exhaust gas purification system 1 will be described with reference to Fig. 2. When the exhaust gas purification system 1 is newly installed, the mode control unit 21 sets the operation mode to the normal mode (step S1), and controls the switching unit 8 to switch the flow path downstream of the branch position of the exhaust path 4 to the flow path on the oxidation treatment device 6 side. At this time, the switching unit 8 opens the flow path on the oxidation treatment device 6 side, and closes the flow path on the bypass path 7 side.

[0035] When the gas consumption device 2 is operated in the normal mode (step S2), fuel gas is supplied to the gas consumption device 2 from the fuel tank via the supply path 3 and the desulfurizer 5. At this time, poisonous components of the fuel gas are adsorbed by the desulfurizer 5, and the desulfurized fuel gas is supplied to the gas consumption device 2. The fuel gas is combusted in the combustion chamber of each cylinder 10 of the gas consumption device 2 during operation, and as a result, exhaust gas is discharged from the gas consumption device 2 to the exhaust path 4.

[0036] Since the flow path of the exhaust path 4 is connected to the oxidation treatment device 6, the exhaust gas is discharged to the oxidation treatment device 6. At this time, harmful components in the exhaust gas are removed by the oxidation treatment device 6, and the purified exhaust gas is discharged from the oxidation treatment device 6. When the gas consumption device 2 is stopped (step S3: Yes), the operation of the exhaust gas purification system 1 also ends.

[0037] Next, an operation example of the regeneration mode of the exhaust gas purification system 1 will be described with reference to Fig. 2. While the gas consumption device 2 is operating in the normal mode, the mode control unit 21 monitors the accumulated amount of poisoning substances in the desulfurizer 5, and when the accumulated amount of poisoning substances exceeds a predetermined accumulated amount threshold (step S4: Yes), the mode control unit 21 switches the operation mode from the normal mode to the regeneration mode (step S5).

[0038] In the regeneration mode, the mode control unit 21 controls the switching unit 8 to switch the flow path downstream of the branch position of the exhaust path 4 to the flow path on the bypass path 7 side (step S6). At this time, the switching unit 8 opens the flow path on the bypass path 7 side and closes the flow path on the oxidation treatment device 6 side. In addition, the mode control unit 21 controls the heat exchanger 9 to operate it.

[0039] When the gas consumption device 2 is operated in the regeneration mode, as in the normal mode, the fuel gas flows through the supply path 3 and the desulfurizer 5, and the fuel gas desulfurized by the desulfurizer 5 is supplied to the gas consumption device 2. The fuel gas is combusted in each cylinder 10 of the gas consumption device 2, and exhaust gas is discharged from the gas consumption device 2 to the exhaust path 4.

[0040] Since the flow path of the exhaust path 4 is connected to the bypass path 7, the exhaust gas is discharged into the bypass path 7. At this time, the exhaust gas passes through the heat exchanger 9 on the way through the bypass path 7, and since the exhaust gas has a high temperature due to the combustion of the fuel gas, the desulfurizer 5 is heated by the heat exchange process of the heat exchanger 9 using the high-temperature exhaust gas (step S7).

[0041] The mode control unit 21 detects the temperature of the desulfurizer 5 by the temperature sensor 18, and based on the detection result, controls the heating by the heat exchanger 9 and the operation of the gas consumption device 2 so that the temperature of the desulfurizer 5 does not exceed a predetermined temperature threshold (for example, about 200 degrees). The mode control unit 21 may appropriately adjust the heating temperature of the desulfurizer 5 by the heat exchanger 9 (i.e., the temperature threshold) depending on the type of desulfurization material of the desulfurizer 5.

[0042] In the desulfurizer 5, when the desulfurizing agent on which the poisoning substances have accumulated is heated by the heat exchanger 9, the poisoning substances are desorbed from the desulfurizing agent, and the desulfurizing agent in the desulfurizer 5 is regenerated. The desorbed poisoning substances are sent to the gas consuming device 2 together with the fuel gas via the supply path 3, and sent to the exhaust path 4 together with the exhaust gas, but are discharged through the bypass path 7 without being sent to the oxidation treatment device 6.

[0043] When a predetermined playback time has elapsed since the start of the playback mode (step S8: Yes), the mode control unit 21 switches the operation mode from the playback mode to the normal mode (step S1).

[0044] In the above-described first embodiment, the exhaust gas purification system 1 is described as an example in which the desulfurizer 5 is disposed in the supply path 3 that supplies the fuel gas to the gas consumption device 2, but the present invention is not limited to this example.

[0045] For example, in another example of the first embodiment, the exhaust gas purification system 1 may have a desulfurizer 5 disposed in the exhaust path 4 that discharges exhaust gas from the gas consumption device 2. In this case, the desulfurizer 5 is disposed in the exhaust path 4 between the exhaust unit 13 of the gas consumption device 2 and the branch position to the bypass path 7, in other words, disposed upstream of the branch position to the bypass path 7 in the exhaust direction of the exhaust gas. Even in this case, the mode control unit 21 controls the switching unit 8 to switch the flow path of the exhaust path 4 to the flow path on the bypass path 7 side in the regeneration mode. Therefore, the poisonous substances desorbed from the desulfurizer 5 during regeneration of the desulfurizer 5 are discharged via the bypass path 7 without being sent to the oxidation treatment device 6.

[0046] As described above, according to the first embodiment of the present invention, the exhaust gas purification system 1 applied to the gas consumption device 2 that consumes fuel gas and emits exhaust gas includes a desulfurizer 5 that stores a desulfurizing agent that removes poisonous components contained in the fuel gas, and an oxidation treatment device 6 that is provided in an exhaust path 4 that discharges exhaust gas from the gas consumption device 2 and stores an oxidation catalyst that oxidizes harmful components contained in the exhaust gas that has passed through the exhaust path 4. The exhaust gas purification system 1 also includes a bypass path 7 branched off from the exhaust path 4, and a switching unit 8 that is provided in the exhaust path 4 and switches the exhaust destination of the exhaust gas from the oxidation treatment device 6 to the bypass path 7 when the desulfurizer 5 is regenerated.

[0047] As a result, according to the exhaust gas purification system 1 of the first embodiment of the present invention, the poisoning substances desorbed from the desulfurizer 5 during regeneration of the desulfurizer 5 are discharged through the bypass path 7 without being sent to the oxidation treatment device 6. Therefore, it is possible to suppress the poisoning of the oxidation treatment device 6 due to the poisoning substances desorbed from the desulfurizer 5 during regeneration, and to reduce the deterioration of the oxidation treatment device 6. In this way, the exhaust gas purification system 1 suppresses the poisoning of the oxidation treatment device 6 by a simple configuration using the bypass path 7, so that the desulfurizer 5 can be applied without a complex configuration. As a result, the exhaust gas purification system 1 can efficiently remove the poisoning components and purify the exhaust gas. The exhaust gas purification system 1 can more reliably block the flow of the poisoning substances to the oxidation treatment device 6 by the damper, valve, etc. of the switching unit 8 during regeneration of the desulfurizer 5.

[0048] In the exhaust gas purification system 1 of the first embodiment of the present invention, the desulfurizer 5 contains a desulfurizing agent that adsorbs poisoning components by physical adsorption, and is provided in the supply path 3 that supplies the fuel gas to the gas consumption device 2. As a result, the desulfurizer 5 desulfurizes the poisoning components from the fuel gas before combustion, which has a lower temperature than the exhaust gas after combustion, so that a desulfurizing agent that adsorbs the poisoning components at a relatively low temperature can be applied. Therefore, the desulfurizer 5 can improve the collection rate of the poisoning components by desulfurizing the poisoning components from the low-temperature fuel gas, compared to the case of desulfurizing the poisoning components from the high-temperature exhaust gas.

[0049] Moreover, such an exhaust gas purification system 1 can apply a low-cost desulfurizer 5 compared to the case of desulfurizing poisoning components from high-temperature exhaust gas. Furthermore, when heating the desulfurizer 5 for regeneration, the exhaust gas purification system 1 can lower the heating of the desulfurizer 5 compared to the case of desulfurizing poisoning components from high-temperature exhaust gas. Therefore, the heating means of the desulfurizer 5 can be made low cost, and the configuration and installation of the heating means can be prevented from becoming complicated.

[0050] The exhaust gas purification system 1 of the first embodiment of the present invention further includes a heat exchanger 9 that is connected to the bypass path 7 and heats the desulfurizer 5 by heat exchange using the exhaust gas flowing through the bypass path 7 during regeneration of the desulfurizer 5. Thus, by applying the heat exchanger 9 as a heating means for the desulfurizer 5, the exhaust gas purification system 1 can reduce the cost of the heating means for the desulfurizer 5 and prevent the configuration and installation of the heating means from becoming complicated.

[0051] In the exhaust gas purification system 1 of the first embodiment of the present invention, the mode control unit 21 calculates the cumulative amount of poisoning components accumulated in the desulfurizer 5 based on the supply amount of fuel gas supplied to the gas consumption device 2 or the exhaust amount of exhaust gas discharged from the gas consumption device, and starts regeneration of the desulfurizer 5 when the cumulative amount exceeds a predetermined threshold. In this way, the exhaust gas purification system 1 can properly grasp the cumulative amount of poisoning components accumulated in the desulfurizer 5, and perform regeneration of the desulfurizer 5 when a decrease in the desulfurization ability of the desulfurizer 5 is detected. Note that the cumulative amount threshold of the cumulative amount of poisoning substances is appropriately set according to the type of desulfurization material of the desulfurizer 5, so that the desulfurizer 5 can be regenerated at an appropriate timing for each desulfurizer 5.

[0052] In the above-described first embodiment, an example has been described in which the present invention is applied to an exhaust gas purification system 1 including a desulfurizer 5, an oxidation treatment device 6, a bypass path 7, a switching unit 8, a heat exchanger 9, and a control unit 20, but the present invention is not limited to this example.

[0053] For example, in another example of the first embodiment, the present invention may be configured as an exhaust gas purification device 100 including a desulfurizer 5, an oxidation treatment device 6, a bypass path 7, a switching unit 8, a heat exchanger 9, and a control unit 20 (see FIG. 1). In this case, in the exhaust gas purification device 100, the desulfurizer 5 is connected to a supply path 3 extending from the gas consumption device 2, and the oxidation treatment device 6, the bypass path 7, and the switching unit 8 are connected to an exhaust path 4 extending from the gas consumption device 2. Alternatively, the exhaust gas purification device 100 may be configured to include the supply path 3 and the exhaust path 4 connected to the gas consumption device 2.

[0054] An exhaust gas purification device 101 according to a second embodiment of the present invention will be described with reference to the drawings. As shown in Fig. 3 and Figs. 6 to 9, the exhaust gas purification device 101 is applied to a gas consumption device 102 such as an engine that consumes a fuel gas such as natural gas, and purifies the exhaust gas discharged from the gas consumption device 102. The gas consumption device 102 is connected to a supply path 103 that supplies fuel gas from a fuel tank or the like, and an exhaust path 104 that discharges exhaust gas. Since the fuel gas contains harmful components such as hydrocarbons that cause air pollution and poisonous components such as sulfur compounds that cause catalyst deterioration, the exhaust gas purification device 101 is configured to remove the harmful components and poisonous components from the exhaust gas generated by the combustion of the fuel gas.

[0055] An exhaust gas purification apparatus 101 according to a second embodiment of the present invention will be described with reference to Fig. 3. The exhaust gas purification apparatus 101 includes a desulfurizer 105 that removes poisonous components such as sulfur compounds contained in the fuel gas, and an oxidation treatment device 106 that oxidizes harmful components such as hydrocarbons contained in the exhaust gas. The exhaust gas purification apparatus 101 is configured to include the exhaust path 104 described above.

[0056] The gas consumption device 102 is composed of an engine that burns and operates using a fuel gas such as liquefied natural gas (LNG). These engines include gas engines that use a fuel gas as fuel, dual fuel engines that operate using a fuel gas and a liquid fuel such as gasoline or diesel fuel, and bi-fuel engines that switch between an operation using a fuel gas and an operation using a liquid fuel. These engines are applied, for example, to a driving source for a ship such as a coastal vessel, and a driving source for a land such as a generator or a heat pump. For example, the gas consumption device 102 is a multi-cylinder engine in which a plurality of cylinders 110 are arranged, and includes an intake section 111, a fuel gas supply section 112, and an exhaust section 113.

[0057] As shown in Fig. 4, each cylinder 110 is composed of a cylinder 115 having a combustion chamber, a piston 116 housed in the cylinder 115, and an ignition device 117. The ignition device 117 is composed of, for example, an ignition plug or an injector for pilot ignition. The cylinder 110 introduces a mixed gas containing a fuel gas into the combustion chamber of the cylinder 115, and by operating the ignition device 117, the mixed gas in the combustion chamber is ignited and burned, and exhaust gas generated by the combustion is discharged. Furthermore, when the ignition device 117 is stopped, no combustion occurs in the cylinder 110, resulting in a misfire.

[0058] The intake section 111 includes an intake manifold 118 connected to each cylinder 110. The intake manifold 118 includes distribution paths 119 connected to cylinders 115 of each cylinder 110, and distributes air supplied from an intake pipe (not shown) and supplies it to the combustion chamber of each cylinder 115. The intake section 111 includes intake valves 120 between each distribution path 119 and each cylinder 115.

[0059] The fuel gas supply unit 112 is provided in the supply path 103 and distributes and supplies the fuel gas supplied from a fuel tank (not shown) or the like via the supply path 103 to the cylinders 115 of the respective cylinders 110 .

[0060] For example, when the gas consumption device 102 is configured as a port injection engine, the fuel gas supply unit 112 supplies the fuel gas to each distribution path 119 of the intake manifold 118 of the intake unit 111, so that the fuel gas is supplied to the combustion chamber of each cylinder 115 through each distribution path 119. As a result, a mixed gas of air supplied from the intake pipe and the fuel gas supplied from the fuel gas supply unit 112 is supplied to the combustion chamber of each cylinder 115 through each distribution path 119 of the intake manifold 118. By opening and closing the intake valve 120, the supply or cutoff of the mixed gas to the combustion chamber of each cylinder 115 is controlled, and the supply amount of the mixed gas is adjusted. Note that each distribution path 119 is provided with a throttle valve (not shown), and the ratio and amount of the mixed gas supplied to the combustion chamber of each cylinder 115 are adjusted by the throttle valve.

[0061] Alternatively, the gas consumption device 102 may be configured as a cylinder direct injection type engine. In this case, the fuel gas supply unit 112 is provided in each cylinder 115, not in the supply path 103, and supplies the fuel gas by directly injecting it into the combustion chamber of each cylinder 115. As a result, in the combustion chamber of each cylinder 115, air supplied from the intake unit 111 and fuel gas supplied from the fuel gas supply unit 112 are mixed to generate a mixed gas. By opening and closing the intake valve 120, the supply or cutoff of air to the combustion chamber of each cylinder 115 is controlled, and the amount of air supplied is adjusted. The fuel gas supply unit 112 may include a fuel valve (not shown), and by opening and closing the fuel valve, the supply or cutoff of fuel gas to the combustion chamber of each cylinder 115 is controlled, and the amount of fuel gas supplied is adjusted.

[0062] The exhaust section 113 includes an exhaust manifold 121 connected to the cylinders 115 of each cylinder 110. The exhaust manifold 121 is also connected to the exhaust path 104, and collects exhaust gas discharged from the combustion chambers of each cylinder 115 and discharges it via the exhaust path 104. The exhaust section 113 includes an exhaust valve 122 between each cylinder 115 and the exhaust manifold 121. By opening and closing the exhaust valve 122, the discharge or blocking of exhaust gas from the combustion chamber of each cylinder 115 is controlled.

[0063] The gas consumption device 102 is configured to set at least one cylinder 110 among the multiple cylinders 110 as a fuel supply cylinder 110a during regeneration of the desulfurizer 105, and to be able to discharge fuel gas through the fuel supply cylinder 110a to the exhaust path 104. At this time, the normal cylinder 110b, which is the cylinder 110 other than the fuel supply cylinder 110a, may perform normal operation to combust the fuel gas and discharge exhaust gas.

[0064] For example, the gas consumption device 102 stops the ignition device 117 of the fuel supply cylinder 110a to misfire the fuel supply cylinder 110a. The gas consumption device 102 opens the intake valve 120 of the fuel supply cylinder 110a to introduce the mixed gas into the combustion chamber of the cylinder 115 of the fuel supply cylinder 110a, but since the ignition device 117 is stopped, the mixed gas is not ignited and is not burned. Note that a mixed gas containing a higher concentration of fuel gas may be introduced into the fuel supply cylinder 110a compared to a case in which the fuel supply cylinder 110a is not misfired.

[0065] The gas consumption device 102 opens the exhaust valve 122 of the fuel supply cylinder 110a, and discharges the mixed gas introduced into the fuel supply cylinder 110a to the exhaust path 104 without burning it. As a result, the gas consumption device 102 discharges the fuel gas contained in the mixed gas to the exhaust path 104. Note that the normal cylinder 110b burns the fuel gas and discharges the exhaust gas to the exhaust path 104, so that the mixed gas from the fuel supply cylinder 110a and the exhaust gas from the normal cylinder 110b are combined in the exhaust path 104, and exhaust gas containing the fuel gas is discharged. Therefore, exhaust gas containing a higher concentration of fuel gas is discharged to the exhaust path 104, compared to the case where the fuel supply cylinder 110a is not misfired.

[0066] The desulfurizer 105 is provided in the exhaust path 104 downstream of the gas consumption device 102 in the exhaust direction of the exhaust gas so that the exhaust gas discharged from the exhaust section 113 passes through the desulfurizer 105. The desulfurizer 105 contains a desulfurizing agent that removes poisoning components such as sulfur compounds. For example, the desulfurizer 105 has a chemical adsorption desulfurizing agent that is made of a direct decomposition type hydrogen sulfide production catalyst and a catalyst containing zirconium oxide and zinc oxide that removes poisoning components.

[0067] When combustion gas containing poisonous components such as sulfur compounds is burned in the gas consumption device 102, the poisonous components remain in the exhaust gas generated by the combustion. Therefore, the desulfurizer 105 removes the poisonous components from the exhaust gas discharged through the exhaust path 104 by adsorbing them to a desulfurizing agent, and poisonous substances consisting of the poisonous components are accumulated in the desulfurizing agent. As a result, the exhaust gas from which the poisonous components have been removed, i.e., the desulfurized exhaust gas, is discharged to the oxidation treatment device 106. In addition, when the desulfurizing agent is heated to a predetermined regeneration temperature or higher, the poisonous substances such as sulfur compounds adsorbed to the desulfurizing agent are desorbed, and the desulfurizer 105 is regenerated.

[0068] The oxidation treatment device 106 is provided in the exhaust path 104 downstream of the desulfurizer 105 in the exhaust gas discharge direction so that the exhaust gas that has passed through the desulfurizer 105 passes through the oxidation treatment device 106. The oxidation treatment device 106 is disposed in close proximity to or in contact with the desulfurizer 105. The oxidation treatment device 106 houses an oxidation catalyst (e.g., a methane oxidation catalyst) that removes harmful components such as hydrocarbons (e.g., methane) and carbon monoxide from the exhaust gas. The oxidation treatment device 106 removes harmful components contained in the exhaust gas discharged through the exhaust path 104 by oxidizing them to carbon dioxide and water using the oxidation catalyst.

[0069] The oxidation catalyst of the oxidation processor 106 generates oxidation reaction heat by oxidizing hydrocarbons such as methane. During normal operation of the gas consumption device 102, only the exhaust gas after burning the fuel gas is introduced into the oxidation processor 106, but during regeneration of the desulfurizer 105, exhaust gas containing unburned fuel gas is introduced into the oxidation processor 106. Therefore, compared to normal operation of the gas consumption device 102, during regeneration of the desulfurizer 105, exhaust gas containing a high concentration of fuel gas, i.e., exhaust gas containing a high concentration of hydrocarbons, is introduced into the oxidation processor 106, and more oxidation reaction heat is generated. The oxidation processor 106 transfers the generated oxidation reaction heat to the desulfurizer 105 in close proximity or contact therewith, thereby heating and regenerating the desulfurizer 105. The oxidation processor 106 may be provided with a transfer member for transferring the oxidation reaction heat to the desulfurizer 105.

[0070] The exhaust gas purification device 101 also includes a control unit 130 as a control section. The control unit 130 is configured to include a computer such as a CPU, and a storage device including a ROM, a RAM, and the like. The storage device stores programs and data for controlling the various components and functions of the exhaust gas purification device 101, and the computer controls the various components and functions by executing arithmetic processing based on the programs and data stored in the storage device. The control unit 130 may be configured by utilizing an engine ECU that controls the engine, which is the gas consumption device 102.

[0071] The exhaust gas purification device 101 operates by switching between a normal mode and a regeneration mode as an operation mode. The control unit 130 functions as a mode control unit 131 that controls the operation mode by executing a program stored in a storage device.

[0072] The mode control unit 131 switches the operation mode to the normal mode when the gas consumption device 102 is operated normally, while switching the operation mode to the regeneration mode when the desulfurizer 105 is regenerated. In addition, in the normal mode, the mode control unit 131 operates the multiple cylinders 110 of the gas consumption device 102 normally. On the other hand, in the regeneration mode, the mode control unit 131 selects the fuel supply cylinder 110a from which fuel gas is discharged among the multiple cylinders 110, and causes the fuel supply cylinder 110a to misfire and operates the normal cylinder 110b normally. Note that the mode control unit 131 may not select only a specific cylinder 110 as the fuel supply cylinder 110a, but may switch the cylinder 110 selected as the fuel supply cylinder 110a every time the regeneration mode is switched a specific number of times.

[0073] For example, the mode control unit 131 usually sets the operation mode to the normal mode, and when the accumulated amount of poisoning substances accumulated in the desulfurizer 105 exceeds a predetermined accumulated amount threshold, the mode control unit 131 switches the operation mode from the normal mode to the regeneration mode. The accumulated amount threshold is appropriately set according to the type of desulfurization material of the desulfurizer 105.

[0074] The mode control unit 131 detects the amount of fuel gas supplied to the gas consumption device 102 or the amount of exhaust gas discharged from the gas consumption device 102, and estimates and calculates the accumulated amount of poisoning substances based on the amount of fuel gas supplied or the amount of exhaust gas discharged. For example, the mode control unit 131 may detect the amount of fuel gas supplied by a fuel gas flow sensor 132 provided in the supply path 103. The control unit 130 is connected to the flow sensor 132 and receives the detected amount of fuel gas from the flow sensor 132. The mode control unit 131 may also detect the amount of exhaust gas supplied by an exhaust gas flow sensor 133 provided in the exhaust path 104. The control unit 130 is connected to the flow sensor 133 and receives the detected amount of exhaust gas from the flow sensor 133.

[0075] Alternatively, the mode control unit 131 may switch the operation mode to the regeneration mode when another abnormality in the desulfurizer 105 is detected or when regeneration of the desulfurizer 105 is instructed by manual operation.

[0076] The mode control unit 131 switches the operation mode from the regeneration mode to the normal mode after completion of regeneration of the desulfurizer 105 in the regeneration mode, for example, after a predetermined regeneration time has elapsed since the start of regeneration of the desulfurizer 105. When switching the operation mode from the regeneration mode to the normal mode, the mode control unit 131 resets the accumulated amount of poisoning substances.

[0077] When regenerating the desulfurizer 105 in the regeneration mode, the mode control unit 131 controls the amount of fuel gas discharged from the gas consumption device 102 to desorb the poisoning substances adsorbed on the desulfurizing agent, and controls the heating of the desulfurizer 105 by the oxidation reaction heat of the oxidation treatment unit 106. For example, the mode control unit 131 adjusts the number of fuel supply cylinders 110a or the amount of fuel gas or the ratio of the mixed gas supplied to the fuel supply cylinders 110a to control the amount of fuel gas discharged from the gas consumption device 102. The exhaust gas purification device 101 includes a temperature sensor 134 that detects the temperature of the desulfurizer 105, located near the desulfurizer 105. The control unit 130 is connected to the temperature sensor 134, and inputs the detected temperature of the desulfurizer 105 from the temperature sensor 134. Then, the mode control unit 131 controls the amount of fuel gas discharged from the gas consumption device 102 so that the detected temperature of the desulfurizer 105 becomes a predetermined regeneration temperature.

[0078] Next, an example of operation of the exhaust gas purification device 101 in the normal mode will be described with reference to Fig. 5. When the exhaust gas purification device 101 or the desulfurizer 105 is newly installed, the mode control unit 131 sets the operation mode to the normal mode (step S11).

[0079] When the gas consuming device 102 is operated in the normal mode (step S12), fuel gas is supplied to the gas consuming device 102 from the fuel tank via the supply path 103. The fuel gas is burned in the combustion chamber of the cylinder 115 of each cylinder 110 of the gas consuming device 102 in operation, and as a result, exhaust gas is discharged from the gas consuming device 102 to the exhaust path 104. The exhaust gas flows through the exhaust path 104 and is introduced into the desulfurizer 105, where poisonous components of the exhaust gas are adsorbed by the desulfurizer 105, and the desulfurized exhaust gas is discharged from the desulfurizer 105.

[0080] The exhaust gas discharged from the desulfurizer 105 flows through the exhaust path 104 and is introduced into the oxidation treatment device 106, where harmful components in the exhaust gas are removed, and the purified exhaust gas is discharged from the oxidation treatment device 106. When the gas consumption device 102 is stopped (step S13: Yes), the operation of the exhaust gas purification device 101 also ends.

[0081] Next, an operation example of the regeneration mode of the exhaust gas purification device 101 will be described with reference to Fig. 5. While the gas consumption device 102 is operating in the normal mode, the mode control unit 131 monitors the accumulated amount of poisoning substances in the desulfurizer 105, and when the accumulated amount of poisoning substances exceeds a predetermined accumulated amount threshold (step S14: Yes), the mode control unit 131 switches the operation mode from the normal mode to the regeneration mode (step S15).

[0082] In the regeneration mode, the mode control unit 131 selects the fuel supply cylinder 110a from which fuel gas is to be discharged among the multiple cylinders 110 and causes it to misfire (step S16). As a result, exhaust gas containing a high concentration of fuel gas is discharged from the gas consumption device 102 to the exhaust path 104. The exhaust gas flows through the exhaust path 104 and is introduced into the desulfurizer 105, where poisonous components of the exhaust gas are adsorbed by the desulfurizer 105, and the desulfurized exhaust gas is discharged from the desulfurizer 105. At this time, the desulfurized exhaust gas still contains a high concentration of fuel gas.

[0083] The exhaust gas discharged from the desulfurizer 105 flows through the exhaust path 104 and is introduced into the oxidation processor 106, where harmful components in the exhaust gas are removed, and the purified exhaust gas is discharged from the oxidation processor 106. At this time, high-concentration hydrocarbons contained in the fuel gas in the exhaust gas are oxidized by the oxidation catalyst in the oxidation processor 106, generating high-temperature oxidation reaction heat which is transferred to the desulfurizer 105 and heats the desulfurizing agent in the desulfurizer 105 (step S17).

[0084] While the desulfurizer 105 is being heated, the mode control unit 131 may detect the temperature of the desulfurizer 105 by the temperature sensor 134, and control the discharge of fuel gas by the fuel supply cylinder 110a of the gas consumption device 102 so that the detected temperature of the desulfurizer 105 becomes a predetermined regeneration temperature. The mode control unit 131 may appropriately adjust the heating temperature of the desulfurizer 105 by the oxidation reaction heat of the oxidation treatment unit 106 (i.e., the regeneration temperature) according to the type of desulfurization material of the desulfurizer 105.

[0085] In the desulfurizer 105, when the desulfurizing agent with the poisoning substances accumulated therein is heated by the heat of the oxidation reaction in the oxidation treatment device 106, the poisoning substances are desorbed from the desulfurizing agent, and the desulfurizing agent in the desulfurizer 105 is thereby regenerated (step S17).

[0086] When a predetermined playback time has elapsed since the start of the playback mode (step S18: Yes), the mode control unit 131 switches the operation mode from the playback mode to the normal mode (step S11).

[0087] However, if the fuel supply cylinder 110a is not operated normally, the total output of the gas consumption device 102 will decrease. Therefore, the mode control unit 131 may determine a regeneration timing that is not easily affected by the output decrease of the gas consumption device 102, and may control the operation mode to switch to the regeneration mode only at that regeneration timing. For example, even if the poisoning substance cumulative amount exceeds a predetermined cumulative amount threshold, when it is necessary to maintain the output of the gas consumption device 102, the mode control unit 131 may control not to switch to the regeneration mode. Furthermore, by estimating the poisoning substance cumulative amount, when it is necessary to maintain the output of the gas consumption device 102 when the poisoning substance cumulative amount exceeds a predetermined cumulative amount threshold based on the operation schedule of the gas consumption device 102, the mode control unit 131 may control to switch to the regeneration mode in advance, or to switch to the regeneration mode at a stage when it is no longer affected by the output decrease of the gas consumption device 102.

[0088] In the above-described second embodiment, the exhaust gas purification device 101 is described using an example in which the condition for switching the operation mode to the regeneration mode is that the accumulated amount of poisoning substances in the desulfurizer 105 exceeds a predetermined accumulated amount threshold value. However, the condition for switching to the regeneration mode in the present invention is not limited to this example.

[0089] As another example of the condition for switching to the regeneration mode, the exhaust gas purification device 101 may switch the operation mode from the normal mode to the regeneration mode when the amount of temperature rise of the exhaust gas that has passed through the oxidation treatment device 106 falls below a predetermined temperature threshold. The temperature threshold is set appropriately depending on the type of the desulfurization material of the desulfurizer 105 and the type of the oxidation catalyst of the oxidation treatment device 106.

[0090] When the accumulation of poisoning substances exceeds the allowable amount, the desulfurizer 105 cannot accumulate the poisoning substances and discharges them, and the poisoning substances discharged from the desulfurizer 105 are introduced into the oxidation processor 106. The poisoning substances introduced into the oxidation processor 106 deteriorate the oxidation catalyst, so that the efficiency of oxidizing the hydrocarbons in the exhaust gas decreases and the heat of the oxidation reaction decreases. Therefore, the temperature rise of the exhaust gas that has passed through the oxidation processor 106 is determined, and the accumulated amount of poisoning substances in the desulfurizer 105 can be estimated based on this temperature rise. When the temperature rise is below the temperature threshold, it can be determined that the accumulated amount of poisoning substances in the desulfurizer 105 exceeds the accumulated amount threshold.

[0091] In this case, the exhaust gas purification device 101 includes an input temperature sensor 135 and an output temperature sensor 136 that detect the temperature of the exhaust gas flowing through the exhaust path 104. The input temperature sensor 135 is provided upstream of the desulfurizer 105 in the exhaust gas discharge direction, and detects the temperature of the exhaust gas input to the desulfurizer 105 and the oxidation treatment device 106. The output temperature sensor 136 is provided downstream of the oxidation treatment device 106 in the exhaust gas discharge direction, and detects the temperature of the exhaust gas output from the desulfurizer 105 and the oxidation treatment device 106.

[0092] The control unit 130 is connected to an input temperature sensor 135 and an output temperature sensor 136, and receives the detected temperatures of the exhaust gas from the input temperature sensor 135 and the output temperature sensor 136. The mode control unit 131 determines the amount of temperature rise of the exhaust gas that has passed through the oxidation treatment device 106 based on the difference between the detected temperatures of the input temperature sensor 135 and the detected temperatures of the output temperature sensor 136, i.e., the temperature difference.

[0093] Alternatively, as another example of a condition for switching to the regeneration mode, the exhaust gas purification device 101 may switch the operation mode from the normal mode to the regeneration mode when a predetermined component of the exhaust gas that has passed through the oxidation treatment device 106 does not satisfy a predetermined component amount threshold. The predetermined component of the exhaust gas is, for example, oxygen, hydrocarbons, sulfur compounds, etc., and the amount of the predetermined component, such as its concentration or amount, is compared with the predetermined component amount threshold. The component amount threshold is set appropriately depending on the type of desulfurization material of the desulfurizer 105 and the type of oxidation catalyst of the oxidation treatment device 106, and the type of the predetermined component.

[0094] The mode control unit 131 can determine the oxidation efficiency of hydrocarbons by the oxidation catalyst of the oxidation treatment unit 106 based on the amounts of predetermined components in the exhaust gas, and estimate the accumulated amount of poisoning substances in the desulfurizer 105 based on the oxidation efficiency of the oxidation treatment unit 106. For example, the mode control unit 131 can determine that the accumulated amount of poisoning substances in the desulfurizer 105 exceeds the accumulated amount threshold when the oxygen concentration of the exhaust gas exceeds the component amount threshold or when the amount of hydrocarbons or sulfur compounds in the exhaust gas exceeds the component amount threshold.

[0095] In this case, the exhaust gas purification device 101 includes an exhaust gas sensor 137 that detects a predetermined component, such as oxygen, hydrocarbons, or sulfur compounds, contained in the exhaust gas flowing through the exhaust path 104. The exhaust gas sensor 137 is provided downstream of the oxidation treatment device 106 in the exhaust gas discharge direction, and detects the amount of the predetermined component in the exhaust gas discharged from the oxidation treatment device 106. The control unit 130 is connected to the exhaust gas sensor 137, and inputs the amount of the predetermined component in the exhaust gas from the exhaust gas sensor 137 to the mode control unit 131 for determination.

[0096] Alternatively, the exhaust gas purification device 101 may switch to the regeneration mode when at least one condition or two or more conditions among the above-mentioned three conditions as the conditions for switching to the regeneration mode are satisfied.

[0097] In addition, in the above-mentioned second embodiment, the exhaust gas purification device 101 has been described by taking as an example a configuration for discharging fuel gas to the fuel supply cylinder 110a, in which the fuel supply cylinder 110a is caused to misfire. However, the fuel gas discharge configuration for the fuel supply cylinder 110a of the present invention is not limited to this example.

[0098] As another example of a fuel gas exhaust configuration for the fuel supply cylinder 110a, when the gas consumption device 102 is a cylinder direct injection engine, the exhaust gas purification device 101 may supply fuel gas to the exhaust manifold 121 by the fuel gas supply unit 112 just before the exhaust valve 122 opens, i.e., just before exhaust.

[0099] Specifically, after the intake valve 120 of the fuel supply cylinder 110a is closed to combust the mixed gas in the combustion chamber of the cylinder 115, the fuel valve of the fuel gas supply unit 112 is opened to supply the fuel gas into the combustion chamber just before the exhaust valve 122 is opened to discharge the exhaust gas. The fuel gas supplied to the combustion chamber is supplied to the exhaust manifold 121 via the exhaust valve 122. This makes it possible to avoid a decrease in the total output of the gas consumption device 102.

[0100] Alternatively, as another example of a fuel gas discharge configuration for the fuel supply cylinder 110a, the exhaust gas purification device 101 may supply fuel gas by the fuel gas supply unit 112 during a valve overlap period in which the intake valve 120 and the exhaust valve 122 of the fuel supply cylinder 110a are simultaneously opened.

[0101] Specifically, during the valve overlap period, the fuel gas supply unit 112 supplies fuel gas to a distribution path 119 connected to the fuel supply cylinder 110a in an intake manifold 118 of the intake unit 111. Since an intake valve 120 of the fuel supply cylinder 110a is open, the fuel gas is supplied to a combustion chamber of a cylinder 115 of the fuel supply cylinder 110a via the distribution path 119. Since an exhaust valve 122 of the fuel supply cylinder 110a is also open, the fuel gas passes through the cylinder 115 of the fuel supply cylinder 110a and is discharged to the exhaust path 104 together with the exhaust gas through the exhaust valve 122 and the exhaust manifold 121. This makes it possible to avoid a decrease in the total output of the gas consumption device 102.

[0102] As described above, according to the second embodiment of the present invention, an exhaust gas purification device 101 applied to a gas consumption device 102 that consumes fuel gas and emits exhaust gas comprises a desulfurizer 105 provided in an exhaust path 104 that discharges exhaust gas from the gas consumption device 102 and containing a desulfurizing agent that removes poisonous components contained in the exhaust gas, an oxidation treatment device 106 provided in the exhaust path 104 downstream of the desulfurizer 105 in the exhaust direction of the exhaust gas, in close proximity to or in contact with the desulfurizer 105, and containing an oxidation catalyst that oxidizes harmful components contained in the exhaust gas, and a mode control unit 131 of a control unit 130 (control unit) that controls the gas consumption device 102 so that fuel gas supplied to at least one fuel supply cylinder 110a among multiple cylinders 110 provided in the gas consumption device 102 is discharged to the exhaust path 104 during regeneration of the desulfurizer 105.

[0103] As a result, according to the exhaust gas purification device 101 of the second embodiment of the present invention, it is possible to discharge high-concentration fuel gas through the fuel supply cylinder 110a and introduce it into the oxidation treatment device 106 without providing a bypass for introducing fuel gas into the oxidation treatment device 106. In addition, since the oxidation treatment device 106 transmits high-temperature oxidation reaction heat generated by the high-concentration fuel gas to the desulfurizer 105, it is possible to heat the desulfurizer 105 without providing a heating means such as a heater or a burner. Therefore, it is possible to regenerate the desulfurizing agent of the desulfurizer 105 at low cost without complicating the configuration and installation of the heating means for heating the desulfurizer 105. As a result, the exhaust gas purification device 101 can efficiently remove poisoning components and purify the exhaust gas.

[0104] The exhaust gas purification apparatus 101 of the second embodiment of the present invention regenerates the desulfurizer 105 when the accumulated amount of poisoning components accumulated in the desulfurizer 105 exceeds a predetermined threshold. This allows the exhaust gas purification apparatus 101 to regenerate the desulfurizer 105 when a decrease in the desulfurization capacity of the desulfurizer 105 is detected. Note that the accumulated amount threshold of the accumulated amount of poisoning substances is appropriately set according to the type of desulfurization material of the desulfurizer 105, so that the desulfurizer 105 can be regenerated at an appropriate timing for each desulfurizer 105.

[0105] In the exhaust gas purification device 101 of the second embodiment of the present invention, for example, the mode control unit 131 controls the gas consumption device 102 so as to extinguish at least one fuel supply cylinder 110a during regeneration of the desulfurizer 105. This makes it possible to discharge high-concentration fuel gas through the fuel supply cylinder 110a and introduce it into the oxidation treatment device 106 without a complex configuration.

[0106] Alternatively, the mode control unit 131 may control the gas consumption device 102 so that the fuel gas supply unit 112 of the gas consumption device 102 configured as a direct injection type supplies fuel gas to at least one fuel supply cylinder 110a immediately before exhaust during regeneration of the desulfurizer 105. This makes it possible to discharge high-concentration fuel gas through the fuel supply cylinder 110a and introduce it into the oxidation treatment device 106 without reducing the overall output of the gas consumption device 102.

[0107] Alternatively, the mode control unit 131 may control the gas consuming device 102 to supply fuel gas to at least one fuel supply cylinder 110a by the fuel gas supply unit 112 of the gas consuming device 102 during a valve overlap period in which the intake valve 120 and the exhaust valve 122 of the cylinder 110 are simultaneously opened during regeneration of the desulfurizer 105. In this case as well, high-concentration fuel gas can be discharged through the fuel supply cylinder 110a and introduced into the oxidation treatment device 106 without reducing the overall output of the gas consuming device 102.

[0108] In the second embodiment, an example has been described in which the exhaust gas purification device 101 has only one desulfurizer 105 upstream of the oxidation treatment device 106 in the exhaust gas discharge direction, but the configuration of the desulfurizer 105 of the present invention is not limited to this example.

[0109] For example, in an exhaust gas purification apparatus 101 of the third embodiment, as shown in Fig. 6 and Fig. 7, a desulfurizer 105 is configured to have two desulfurizers, a first desulfurizer 141 and a second desulfurizer 142. In the third embodiment, a description of the same configuration as in the second embodiment will be omitted.

[0110] Each of the first desulfurizer 141 and the second desulfurizer 142 is configured similarly to the desulfurizer 105 of the second embodiment. The first desulfurizer 141 and the second desulfurizer 142 are disposed adjacent to or in contact with the oxidation treatment device 106, sandwiching the oxidation treatment device 106 therebetween, and are connected to the oxidation treatment device 106. A temperature sensor 134 that detects the temperature of the desulfurizer 105 is provided for each of the first desulfurizer 141 and the second desulfurizer 142.

[0111] The oxidation treatment unit 106 transfers the heat of oxidation reaction generated when the exhaust gas is oxidized to the first desulfurizer 141 or the second desulfurizer 142 located nearby or in contact with the first desulfurizer 141 or the second desulfurizer 142, thereby heating and regenerating the first desulfurizer 141 or the second desulfurizer 142. The oxidation treatment unit 106 may be provided with a transfer member that transfers the heat of oxidation reaction to the first desulfurizer 141 and the second desulfurizer 142.

[0112] The exhaust gas purification device 101 has a first branch path 143 and a second branch path 144 branched from the exhaust path 104 at the same branch position. The exhaust path 104 has an upstream exhaust path 104a on the gas consumption device 102 side from the branch position, and a downstream exhaust path 104b on the outside air side from the branch position, and the exhaust path 104, the first branch path 143, and the second branch path 144 form a cross-shaped path. The first desulfurizer 141 and the second desulfurizer 142 are connected to the first branch path 143 and the second branch path 144, respectively. Note that FIG. 6 and FIG. 7 show an example in which the downstream exhaust path 104b passes through the back side of the oxidation treatment device 106, that is, the downstream exhaust path 104b is not connected to the oxidation treatment device 106. By arranging the downstream exhaust path 104b adjacent to the oxidation treatment device 106, the heat retention of the oxidation treatment device 106 can be improved by the exhaust gas flowing through the downstream exhaust path 104b.

[0113] The exhaust gas purification device 101 of the third embodiment has a first flow path 145 (see FIG. 6) from the upstream exhaust path 104a via the first branch path 143, and a second flow path 146 (see FIG. 7) from the upstream exhaust path 104a via the second branch path 144, as flow paths for discharging exhaust gas from the gas consumption device 102. In the first flow path 145, the exhaust gas is introduced from the first branch path 143 to the first desulfurizer 141, the oxidation treatment device 106, and the second desulfurizer 142, and is discharged to the downstream exhaust path 104b via the second branch path 144. In the second flow path 146, the exhaust gas is introduced from the second branch path 144 to the second desulfurizer 142, the oxidation treatment device 106, and the first desulfurizer 141, and is discharged to the downstream exhaust path 104b via the first branch path 143.

[0114] The exhaust gas purification device 101 of the third embodiment includes a switching unit 147 at a branch position to the first desulfurizer 141 and the second desulfurizer 142 in the exhaust path 104. The switching unit 147 is composed of a valve, a damper, or the like that opens and closes the flow path. The switching unit 147 may be composed of a three-way valve that outputs the first branch path 143 or the second branch path 144 to the upstream exhaust path 104a, and a three-way valve that outputs the first branch path 143 or the second branch path 144 to the downstream exhaust path 104b. The switching unit 147 is connected to the control unit 130, and is controlled by the mode control unit 131 to switch between the first flow path 145 and the second flow path 146.

[0115] 6, when switching to the first flow path 145, the switching unit 147 closes the second branch path 144 and the downstream exhaust path 104b when viewed from the upstream exhaust path 104a, and closes the upstream exhaust path 104a and the first branch path 143 when viewed from the downstream exhaust path 104b. As a result, the switching unit 147 connects the upstream exhaust path 104a and the first branch path 143, and connects the second branch path 144 and the downstream exhaust path 104b.

[0116] 7, when switching to the second flow path 146, the switching unit 147 closes the first branch path 143 and the downstream exhaust path 104b when viewed from the upstream exhaust path 104a, and closes the upstream exhaust path 104a and the second branch path 144 when viewed from the downstream exhaust path 104b. As a result, the switching unit 147 connects the upstream exhaust path 104a and the second branch path 144, and connects the first branch path 143 and the downstream exhaust path 104b.

[0117] In the third embodiment, the conditions under which the mode control unit 131 switches the operation mode between the normal mode and the playback mode may be set in the same manner as in the second embodiment.

[0118] The exhaust gas discharge operation in the normal mode of the third embodiment will be described below. When switching the operation mode to the normal mode, the mode control unit 131 switches to the first flow path 145 by the switching unit 147. The exhaust gas flowing through the first flow path 145 is first introduced into the first desulfurizer 141, where poisonous components of the exhaust gas are adsorbed by the first desulfurizer 141, and the desulfurized exhaust gas is discharged from the first desulfurizer 141. The exhaust gas discharged from the first desulfurizer 141 is introduced into the oxidation treatment unit 106, where harmful components of the exhaust gas are removed by the oxidation treatment unit 106, and the purified exhaust gas is discharged from the oxidation treatment unit 106. The purified exhaust gas is discharged to the downstream exhaust path 104b via the second desulfurizer 142 and the second flow path 146.

[0119] The exhaust gas discharge operation in the regeneration mode of the third embodiment will be described below. When switching the operation mode to the regeneration mode, the mode control unit 131 switches to the second flow path 146 by the switching unit 147. In the regeneration mode, exhaust gas containing a higher concentration of fuel gas than in the normal mode is discharged from the gas consumption device 102 and flows through the second flow path 146 of the exhaust path 104. The exhaust gas flowing through the second flow path 146 is first introduced into the second desulfurizer 142, where poisonous components of the exhaust gas are adsorbed by the second desulfurizer 142, and the desulfurized exhaust gas is discharged from the second desulfurizer 142. At this time, the desulfurized exhaust gas still contains a high concentration of fuel gas.

[0120] The exhaust gas discharged from the second desulfurizer 142 is introduced into the oxidation processor 106, where harmful components of the exhaust gas are removed, and the purified exhaust gas is discharged from the oxidation processor 106. At this time, high-concentration hydrocarbons contained in the fuel gas in the exhaust gas are oxidized by the oxidation catalyst of the oxidation processor 106, generating high-temperature oxidation reaction heat that is transferred to the first desulfurizer 141 and heating the desulfurizing agent of the first desulfurizer 141. In the first desulfurizer 141, the desulfurizing agent in which the poisoning substances have accumulated is heated by the oxidation reaction heat of the oxidation processor 106, and the poisoning substances are desorbed from the desulfurizing agent, whereby the desulfurizing agent of the first desulfurizer 141 is regenerated. The purified exhaust gas introduced into the first desulfurizer 141 is discharged together with the desorbed poisoning substances, and is discharged to the downstream exhaust path 104b via the first flow path 145.

[0121] After completing the regeneration of the first desulfurizer 141 in the regeneration mode, the mode control unit 131 switches the operation mode from the regeneration mode to the normal mode, and also switches the operation mode to the first flow path 145 by the switching unit 147 .

[0122] As described above, in the third embodiment, in both the normal mode and the regeneration mode, the first desulfurizer 141 or the second desulfurizer 142 is always disposed upstream of the oxidation treatment device 106 in the exhaust gas discharge direction, so that it is possible to always avoid introduction of poisonous substances in the exhaust gas into the oxidation treatment device 106. Also, in the regeneration mode, the first desulfurizer 141 downstream of the oxidation treatment device 106 can be regenerated while the exhaust gas is desulfurized by the second desulfurizer 142 upstream of the oxidation treatment device 106 in the exhaust direction.

[0123] In the third embodiment, an example has been described in which the switching unit 147 switches to the first flow path 145 in the normal mode and switches to the second flow path 146 in the regeneration mode, but the present invention is not limited to this example. That is, the present invention does not limit the flow paths used in the normal mode and the regeneration mode to the first flow path 145 and the second flow path 146, respectively, and the first flow path 145 or the second flow path 146 may be selectively switched as necessary.

[0124] In another example of the third embodiment, the switching unit 147 may switch to the second flow path 146 in the normal mode, and switch to the first flow path 145 in the regeneration mode. In this case, the flow of the exhaust gas is reversed from that in the above example, and the functions of the first desulfurizer 141 and the second desulfurizer 142 are also reversed, but the same effect as in the above example is achieved. Even in this case, in both the normal mode and the regeneration mode, the first desulfurizer 141 or the second desulfurizer 142 is always arranged upstream of the oxidation treatment device 106 in the exhaust direction of the exhaust gas, so that the introduction of poisonous substances in the exhaust gas into the oxidation treatment device 106 can always be avoided. In addition, in the regeneration mode, the second desulfurizer 142 downstream of the oxidation treatment device 106 can be regenerated while the first desulfurizer 141 upstream of the oxidation treatment device 106 in the exhaust direction desulfurizes the exhaust gas.

[0125] When the first flow path 145 is used in the normal mode, the mode control unit 131 may monitor the frequency of use of the first desulfurizer 141 in normal operation, and when the frequency of use reaches a predetermined frequency threshold, switch to use the second flow path 146 in the normal mode. Similarly, when the second flow path 146 is used in the normal mode, the mode control unit 131 may monitor the frequency of use of the second desulfurizer 142 in normal operation, and when the frequency of use reaches a predetermined frequency threshold, switch to use the first flow path 145 in the normal mode. The frequency of use of the first desulfurizer 141 or the second desulfurizer 142 may be determined, for example, by the operating time or engine speed of the gas consumption device 102, the total use time or exhaust gas flow rate of the first desulfurizer 141 or the second desulfurizer 142, the number of regenerations or the total regeneration time, the total integrated amount of poisoning substances, etc.

[0126] In the third embodiment, an example has been described in which the mode control unit 131 switches to the first flow path 145 by the switching unit 147 after the regeneration of the first flow path 145 is completed in the regeneration mode, but the present invention is not limited to this example. In another example, even if the operation mode is switched from the regeneration mode to the normal mode after the regeneration of the first flow path 145 is completed in the regeneration mode, the mode control unit 131 may maintain the second flow path 146 without switching to the first flow path 145, and use the second flow path 146 in the normal mode. Similarly, even if the operation mode is switched from the regeneration mode to the normal mode after the regeneration of the second flow path 146 is completed in the regeneration mode, the mode control unit 131 may maintain the first flow path 145 without switching to the second flow path 146, and use the first flow path 145 in the normal mode.

[0127] In the third embodiment, when the temperature rise amount of the exhaust gas that has passed through the oxidation treatment device 106 is determined as a condition for switching to the regeneration mode in the same manner as in the second embodiment, a first temperature sensor 148 is provided in the first branch path 143 near the first desulfurizer 141, and a second temperature sensor 149 is provided in the second branch path 144 near the second desulfurizer 142. When the first flow path 145 is used in the normal mode, the first temperature sensor 148 and the second temperature sensor 149 are used in the same manner as the input temperature sensor 135 and the output temperature sensor 136 in the second embodiment. On the other hand, when the second flow path 146 is used in the normal mode, the first temperature sensor 148 and the second temperature sensor 149 are used in the same manner as the output temperature sensor 136 and the input temperature sensor 135 in the second embodiment.

[0128] Furthermore, in the third embodiment, when a predetermined component of the exhaust gas that has passed through the oxidation treatment device 106 is determined as a condition for switching to the regeneration mode in the same manner as in the second embodiment, a first exhaust gas sensor 150 is provided in the first branch path 143 near the first desulfurizer 141, and a second exhaust gas sensor 151 is provided in the second branch path 144 near the second desulfurizer 142. When the first flow path 145 is used in the normal mode, the first exhaust gas sensor 150 is used in the same manner as the exhaust gas sensor 137 in the second embodiment. On the other hand, when the second flow path 146 is used in the normal mode, the second exhaust gas sensor 151 is used in the same manner as the exhaust gas sensor 137 in the second embodiment.

[0129] In the third embodiment in which the first desulfurizer 141, the oxidation treatment device 106, and the second desulfurizer 142 are arranged in series, the first branch path 143 that introduces exhaust gas into the first desulfurizer 141 in the normal mode also serves as a path for discharging the exhaust gas purified by the oxidation treatment device 106 from the first desulfurizer 141 in the regeneration mode. In addition, in the third embodiment, the second branch path 144 that introduces exhaust gas into the second desulfurizer 142 in the regeneration mode also serves as a path for discharging the exhaust gas purified by the oxidation treatment device 106 from the second desulfurizer 142 in the normal mode. However, in the present invention, the path for discharging the exhaust gas purified by the oxidation treatment device 106 is not limited to the example in which the first branch path 143 and the second branch path 144 are used together as in the third embodiment.

[0130] For example, as shown in Fig. 8, the exhaust gas purification apparatus 101 of the fourth embodiment includes a third branch path 160 that discharges the exhaust gas purified by the oxidation treatment device 106 from the second desulfurizer 142 in the normal mode. Also, as shown in Fig. 9, the exhaust gas purification apparatus 101 of the fourth embodiment includes a fourth branch path 161 that discharges the exhaust gas purified by the oxidation treatment device 106 from the first desulfurizer 141 in the regeneration mode. In the fourth embodiment, a description of the same configuration as in the second or third embodiment will be omitted.

[0131] The third branch path 160 branches off from the first branch path 143 and merges into the downstream exhaust path 104b. The fourth branch path 161 branches off from the second branch path 144 and merges into the downstream exhaust path 104b. In the exhaust path 104, the upstream exhaust path 104a branches off into the first branch path 143 and the second branch path 144, but is not directly connected to the downstream exhaust path 104b.

[0132] In the fourth embodiment, the first flow path 145 and the second flow path 146 that discharge the exhaust gas from the gas consumption device 102 are different from those in the third embodiment. In the first flow path 145 that passes through the first branch path 143 from the upstream exhaust path 104a, as shown in FIG. 8, the exhaust gas is introduced from the first branch path 143 to the first desulfurizer 141, the oxidation treatment device 106, and the second desulfurizer 142, and is discharged to the downstream exhaust path 104b via the fourth branch path 161. In the second flow path 146 that passes through the second branch path 144 from the upstream exhaust path 104a, as shown in FIG. 9, the exhaust gas is introduced from the second branch path 144 to the second desulfurizer 142, the oxidation treatment device 106, and the first desulfurizer 141, and is discharged to the downstream exhaust path 104b via the third branch path 160.

[0133] In the fourth embodiment, the configuration for switching the flow path for discharging exhaust gas from the gas consumption device 102 is different from that of the switching unit 147 of the third embodiment. The exhaust gas purification device 101 includes a first switching unit 162 in the first branch path 143 near the upstream exhaust path 104a, and a second switching unit 163 in the second branch path 144 near the upstream exhaust path 104a. The exhaust gas purification device 101 also includes a third switching unit 164 in the third branch path 160 near the first branch path 143, and a fourth switching unit 165 in the fourth branch path 161 near the second branch path 144.

[0134] The first switching unit 162, the second switching unit 163, the third switching unit 164, and the fourth switching unit 165 are configured with a valve, a damper, or the like that opens and closes the flow path. The first switching unit 162 and the second switching unit 163 may be configured with a three-way valve that outputs the first branch path 143 or the second branch path 144 to the upstream exhaust path 104a. The first switching unit 162, the second switching unit 163, the third switching unit 164, and the fourth switching unit 165 are connected to the control unit 130, and are controlled by the mode control unit 131 to switch between opening and closing of each path. The first switching unit 162 switches between discharging the exhaust gas to the first branch path 143 and blocking, and the second switching unit 163 switches between discharging the exhaust gas to the second branch path 144 and blocking. The third switch 164 switches between discharging the exhaust gas to the third branch path 160 and blocking it, and the fourth switch 165 switches between discharging the exhaust gas to the fourth branch path 161 and blocking it.

[0135] For example, when switching to the first flow path 145, as shown in FIG. 8, the first switching unit 162 opens the first branch path 143 and the second switching unit 163 closes the second branch path 144, thereby communicating the upstream exhaust path 104a with the first branch path 143. In addition, the third switching unit 164 closes the third branch path 160 and the fourth switching unit 165 opens the fourth branch path 161, thereby communicating the fourth branch path 161 with the downstream exhaust path 104b. At this time, the mode control unit 131 may control the first switching unit 162 and the second switching unit 163 so that the first branch path 143 is opened and the second branch path 144 is closed at the same time. In addition, the mode control unit 131 may control the third switching unit 164 and the fourth switching unit 165 so that the third branch path 160 is closed and the fourth branch path 161 is opened at the same time.

[0136] On the other hand, when switching to the second flow path 146, as shown in FIG. 9, the first switching unit 162 closes the first branch path 143 and the second switching unit 163 opens the second branch path 144, thereby communicating the upstream exhaust path 104a with the second branch path 144. In addition, the third switching unit 164 opens the third branch path 160 and the fourth switching unit 165 closes the fourth branch path 161, thereby communicating the third branch path 160 with the downstream exhaust path 104b. At this time, the mode control unit 131 may control the first switching unit 162 and the second switching unit 163 so that the first branch path 143 is closed and the second branch path 144 is opened simultaneously. In addition, the mode control unit 131 may control the third switching unit 164 and the fourth switching unit 165 so that the third branch path 160 is opened and the fourth branch path 161 is closed simultaneously.

[0137] In the fourth embodiment, the conditions under which the mode control unit 131 switches the operation mode between the normal mode and the regeneration mode may be set in the same manner as in the third embodiment. The first flow path 145 and the second flow path 146 in the fourth embodiment function in the same manner as in the third embodiment. The exhaust gas discharge operation in the normal mode and the regeneration mode in the fourth embodiment is similar to that in the third embodiment, and therefore a description thereof will be omitted. Also, in the fourth embodiment, the flow paths used in the normal mode and the regeneration mode are not limited to the first flow path 145 and the second flow path 146, respectively, and the first flow path 145 and the second flow path 146 may be selectively switched as necessary, similar to the third embodiment.

[0138] As described above, according to the third or fourth embodiment of the present invention, in the exhaust gas purification device 101, the desulfurizer 105 has the first desulfurizer 141 and the second desulfurizer 142, and the oxidation treatment device 106 is provided between the first desulfurizer 141 and the second desulfurizer 142. The mode control unit 131 switches between a first flow path 145 that discharges exhaust gas from the first desulfurizer 141, the oxidation treatment device 106, and the second desulfurizer 142 in this order, and a second flow path 146 that discharges exhaust gas from the second desulfurizer 142, the oxidation treatment device 106, and the first desulfurizer 141 in this order.

[0139] As a result, according to the exhaust gas purification device 101 of the present invention, the first desulfurizer 141 or the second desulfurizer 142 is always disposed upstream of the oxidation treatment device 106 in the exhaust direction of the exhaust gas, so that it is possible to always avoid introduction of poisonous substances in the exhaust gas into the oxidation treatment device 106. Also, in the regeneration mode, the first desulfurizer 141 or the second desulfurizer 142 upstream of the oxidation treatment device 106 in the exhaust direction desulfurizes the exhaust gas, while regeneration of the second desulfurizer 142 downstream of the oxidation treatment device 106 can be performed. As a result, the exhaust gas purification device 101 can more efficiently remove poisonous components and purify the exhaust gas.

[0140] According to the exhaust gas purification device 101 of the third or fourth embodiment of the present invention, the mode control unit 131 switches between the first flow path 145 and the second flow path 146 when starting regeneration of the desulfurizer 105, and further switches between the first flow path 145 and the second flow path 146 when ending regeneration of the desulfurizer 105. As a result, after switching from the regeneration mode to the normal mode, the first desulfurizer 141 or the second desulfurizer 142 after regeneration is always disposed upstream of the oxidation treatment device 106 in the exhaust direction of the exhaust gas. Therefore, in the resumed normal mode, desulfurization can be performed by the refreshed first desulfurizer 141 or the second desulfurizer 142, and poisoning components can be removed more efficiently.

[0141] Furthermore, 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 exhaust gas purification systems and exhaust gas purification devices involving such modifications are also included in the technical concept of the present invention. [Explanation of symbols]

[0142] 1 Exhaust gas purification system 2, 102 Gas consumption device 3, 103 Supply Channel 4, 104 Exhaust route 5, 105 Desulfurizer 6, 106 Oxidation treatment device 7. Bypass Route 8 Switching section 9 Heat exchanger 10 cylinders 10a Fuel supply cylinder 10b Normal cylinder 20, 130 Control unit 21, 131 Mode control section 100, 101 Exhaust gas purification device

Claims

1. An exhaust gas purification device that is applied to a gas consumption device that consumes fuel gas and emits exhaust gas, a desulfurizer that is provided in an exhaust path that discharges the exhaust gas from the gas consumption device and that contains a desulfurizing agent that removes poisonous components contained in the exhaust gas; an oxidation treatment device that is provided in the exhaust path downstream of the desulfurizer in a discharge direction of the exhaust gas, in close proximity to or in contact with the desulfurizer, and that contains an oxidation catalyst that oxidizes harmful components contained in the exhaust gas; A control unit that controls the gas consumption device so that the fuel gas supplied to at least one cylinder among a plurality of cylinders provided in the gas consumption device is discharged to the exhaust path during regeneration of the desulfurizer; An exhaust gas purification device comprising:

2. 2. The exhaust gas purification device according to claim 1, wherein the desulfurizer is regenerated when an integrated amount of the poisoning components accumulated in the desulfurizer exceeds a predetermined threshold value.

3. 3. The exhaust gas purification device according to claim 1, wherein the control unit controls the gas consumption device so as to cause the at least one cylinder to misfire during regeneration of the desulfurizer.

4. The exhaust gas purification device according to claim 1 or 2, characterized in that the control unit controls the gas consumption device so that, during regeneration of the desulfurizer, the fuel gas is supplied to at least one cylinder by a fuel gas supply unit of the gas consumption device, which is configured as a direct injection type into a cylinder, immediately before exhaust.

5. The exhaust gas purification device according to claim 1 or 2, characterized in that the control unit controls the gas consumption device so that the fuel gas is supplied to at least one cylinder by the fuel gas supply unit of the gas consumption device during a valve overlap period in which the intake valve and exhaust valve of the cylinder are simultaneously opened during regeneration of the desulfurizer.

6. The desulfurizer has a first desulfurizer and a second desulfurizer, The oxidation treatment unit is provided between the first desulfurizer and the second desulfurizer, 6. The exhaust gas purification device according to claim 1, wherein the control unit switches between a first flow path that discharges the exhaust gas in the order of the first desulfurizer, the oxidation treatment device, and the second desulfurizer, and a second flow path that discharges the exhaust gas in the order of the second desulfurizer, the oxidation treatment device, and the first desulfurizer.

7. The exhaust gas purification device according to claim 6, characterized in that the control unit switches between the first flow path and the second flow path when starting regeneration of the desulfurizer, and further switches between the first flow path and the second flow path when ending regeneration of the desulfurizer.

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