Exhaust gas aftertreatment system for an engine designed as a gas engine or a dual-fuel engine, the engine, and its operating method
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- EVERLLENCE SE
- Filing Date
- 2022-08-04
- Publication Date
- 2026-08-03
Smart Images
Figure 0007898987000001 
Figure 0007898987000002
Abstract
Description
Technical Field
[0001] The present invention relates to an exhaust gas after-treatment system for an engine designed as a gas engine or a dual-fuel engine. Further, the present invention relates to an engine designed as a gas engine or a dual-fuel engine, and a method of operating an exhaust gas after-treatment system or an engine.
Background Art
[0002] Large engines, such as those used as internal combustion engines of ships, are increasingly being embodied as gas engines or dual-fuel engines. In a gas engine, a gas fuel, such as natural gas, is burned. In a dual-fuel engine, a gas fuel, such as natural gas, can be burned in a gas fuel operation mode, and a liquid fuel, such as diesel fuel, can be burned in a liquid fuel operation mode.
[0003] The exhaust gas of such large engines must be purified. For this purpose, the engine is provided with an exhaust gas after-treatment system. There is a need for a compact design exhaust gas after-treatment system for an engine designed as a gas engine or a dual-fuel engine, particularly a large engine preferentially used as a propulsion unit of a ship.
Prior Art Documents
Patent Documents
[0004]
Patent Document 1
Patent Document 2
Summary of the Invention
Problems to be Solved by the Invention
[0005] In view of such requirements, the present invention aims to provide a novel type of exhaust gas aftertreatment system for an engine designed as a gas engine or a dual-fuel engine equipped with such an exhaust gas aftertreatment system. [Means for solving the problem]
[0006] This objective is achieved by the exhaust gas aftertreatment system described in claim 1.
[0007] The exhaust gas aftertreatment system according to the present invention is equipped with a catalyst through which exhaust gas can flow.
[0008] Furthermore, the exhaust gas aftertreatment system according to the present invention includes a control tube that extends through a recess in the catalyst, and this control tube is movable relative to the catalyst and can also pass exhaust gas through it.
[0009] Furthermore, the exhaust gas aftertreatment system according to the present invention includes an actuator that can move a control tube relative to a catalyst in accordance with at least one operating condition of the engine and / or at least one operating condition of the exhaust gas aftertreatment system, wherein at a first relative position of the control tube with respect to the catalyst, exhaust gas can flow through the catalyst but not through the control tube, and at a second relative position of the control tube with respect to the catalyst, exhaust gas can flow through the control tube but not through the catalyst.
[0010] In the exhaust gas aftertreatment system according to the present invention, the control pipe penetrates a recess in the catalyst and is integrated with the catalyst so as to be movable relative to the catalyst. At a first relative position of the control pipe, the control pipe allows the flow of exhaust gas through the catalyst, and at a second relative position of the control pipe, the control pipe obstructs the flow of exhaust gas through the catalyst but allows the flow of exhaust gas through the control pipe itself. Such an exhaust gas aftertreatment system requires little installation space. Bypass pipes, insulations, flaps, rupture discs, and control valves for bypass pipes can be omitted.
[0011] Preferably, the catalyst is a ring catalyst, the radially inner side of which is defined by a first catalyst tube in a region of recess for receiving a control tube, and the radially outer side of which is defined by a second catalyst tube and / or pressure reactor, the first axial end having an exhaust gas inlet side and the second axial end having an exhaust gas outlet side. Such a catalyst is particularly preferred to ensure a compact design of the exhaust gas aftertreatment system.
[0012] The control tube preferably has a first portion that supports a first closure body that allows flow through the catalyst at a first relative position of the control tube and obstructs flow through the catalyst at a second relative position of the control tube. This configuration also contributes to providing a compact design for the exhaust gas aftertreatment system.
[0013] The control tube is preferably a second part that supports a second sealing body that seals the gap between the control tube and the catalyst at the first relative position of the control tube. This has the advantage of reducing the installation space of the exhaust gas aftertreatment system.
[0014] The control pipe preferably includes a third portion which is closed at a first relative position of the control pipe and open at a second relative position of the control pipe. This configuration also contributes to reducing the installation space required for the exhaust gas aftertreatment system.
[0015] Preferably, the exhaust gas aftertreatment system includes a spray device for a regeneration agent, which can introduce the regeneration agent into the catalyst at a first relative position of the control tube to the catalyst and a second relative position of the control tube to the catalyst. This spray device makes it possible to introduce the regeneration agent into the catalyst while keeping the exhaust gas aftertreatment system design compact.
[0016] The exhaust gas aftertreatment system preferably includes at least one sensor and a control unit to detect at least one operating position of the engine and / or at least one operating condition of the exhaust gas aftertreatment system and to control an actuator independently of at least one operating condition of the engine and / or at least one operating condition of the exhaust gas aftertreatment system. Thereby, the exhaust gas aftertreatment system can be operated particularly advantageously to pass the exhaust gas through the catalyst or, in the sense of a bypass operation, past the catalyst and through the control pipe. Thereby, the exhaust gas aftertreatment system is automatically adapted according to at least one operating condition of the exhaust gas aftertreatment system and / or at least one operating condition of the engine and can operate the exhaust gas aftertreatment system in either a catalyst mode or a bypass mode for the catalyst.
[0017] The engine according to the present invention is defined in claim 9.
[0018] The method according to the present invention for operating an exhaust gas aftertreatment system is defined in claim 10.
[0019] Preferred further developments of the present invention result from the dependent claims and the following detailed description.
Brief Description of the Drawings
[0020] [Figure 1] It is a diagram showing a first state of an exhaust gas aftertreatment system according to the present invention. [Figure 2] It is a diagram showing a second state of the exhaust gas aftertreatment system of FIG. 1.
Embodiments of the Invention
[0021] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings, but the present invention is not limited thereto.
[0022] The present invention relates to an engine having an exhaust gas aftertreatment system and a fuel supply system for an engine designed as a gas engine or a dual fuel engine. Further, the present invention relates to an engine designed as a gas engine or a dual fuel engine, and a method of operating an exhaust gas aftertreatment system and the engine.
[0023] FIGS. 1 and 2 schematically show a preferred exemplary embodiment of an exhaust gas aftertreatment system 1 according to the present invention for a gas engine or a dual fuel engine, particularly a large engine used as a propulsion unit for a ship, which is not shown in detail.
[0024] FIGS. 1 and 2 show an exhaust line 2 led from an engine not shown in the direction of the exhaust gas aftertreatment system 1.
[0025] The exhaust gas aftertreatment system 1 includes a catalyst 3. Exhaust gas can flow through the catalyst 3.
[0026] Further, the exhaust gas aftertreatment system 1 includes a control pipe 4 extending into a recess 5 of the catalyst 3. The control pipe 4 can move relative to the catalyst 3 and is likewise capable of flowing exhaust gas. The control pipe 4 is guided axially movably within the recess 5 of the catalyst 3.
[0027] Further, the exhaust gas aftertreatment system 1 includes an actuator 6. The actuator 6 can move the control pipe 4 relative to the catalyst 3 in accordance with at least one operating condition of the engine and / or at least one operating condition of the exhaust gas aftertreatment system 1.
[0028] In a first relative position I of the control pipe 4 with respect to the catalyst 3 (see FIG. 1), exhaust gas can flow through the catalyst 3 but cannot flow through the control pipe 4.
[0029] In a second relative position II of the control pipe 4 with respect to the catalyst 3 (see FIG. 2), exhaust gas can flow through the control pipe 4 but cannot flow through the catalyst 3.
[0030] Catalyst 3 is a cyclic catalyst. Catalyst 3 is defined radially inward by a first catalyst tube 7 within a recess 5 that receives a control tube 4. Catalyst 3 is defined radially outward by a second catalyst tube 8 and / or a pressure reactor 9. In Figures 1 and 2, portions 9a and 9b of the pressure reactor 9 extend axially on both sides of catalyst 3 or the second catalyst tube 8.
[0031] Catalyst 3 has two axial ends that are positioned opposite each other. The first axial end 10 of catalyst 3 has an inlet side for exhaust gas. The second axial end 11 of catalyst 3, which is opposite to catalyst 3, has an outlet side for exhaust gas.
[0032] In particular, as shown in Figure 1, when the control pipe 4 is in a first relative position to the catalyst 3, the exhaust gas A flowing into the exhaust gas aftertreatment system 1 via the exhaust pipe 2 first flows into portion 9a of the pressure reactor 9, and from there can flow into the catalyst 3 via the inlet side formed at the first axial end 10. The exhaust gas A that has passed through the catalyst 3 flows out of the catalyst 3 via the outlet side formed at the opposing second axial end 11, flows into portion 9b of the pressure reactor 9, and from this portion 9b flows further toward the exhaust pipe 12 and is discharged from the exhaust gas aftertreatment system 1.
[0033] The control tube 4 is equipped with a first closure 13 on a first portion 4a. At the first relative position of the control tube 4 with respect to the catalyst 3 (see Figure 1), the first closure 13 allows exhaust gas A to flow into the catalyst 3, thus opening the inlet side of the catalyst 3 formed at the first axial end 10 to allow the exhaust gas to flow. In contrast, at the second relative position of the control tube 4 (see Figure 2), the first closure 13 prevents exhaust gas from flowing into the catalyst 3, and therefore at this position, the first closure 13 closes the inlet side of the catalyst 3 formed at the first axial end 10 to allow the exhaust gas to flow. The first portion 4a of the control tube 4 supports the first closure 13 radially outward and projects from the catalyst 3 to the first axial end 10 of the catalyst 3. Thus, the first portion 4a of the control tube 4 protrudes from the control tube 4 to the first axial end 10 of the catalyst 3.
[0034] In the second section 4b, the control tube 4 includes a second seal 14. This second seal 14 seals the gap 15 formed between the control tube 4 and the catalyst tube 7 located radially inward at the first relative position of the control tube 4 with respect to the catalyst 3. This is not necessary at the second relative position of the control tube 4 with respect to the catalyst 3 (see Figure 2).
[0035] In the third section 4c, the control tube 4 has recesses 16. In the first relative position of the control tube 4 with respect to the catalyst 3 (see Figure 1), these recesses 16 are closed, in particular, via the inner catalyst tube 7 and the second closure 14. In contrast, in the second relative position between the control tube 4 and the catalyst 3 (see Figure 2), these recesses 16 in the third section 4c of the control tube 4 are open. In the state shown in Figure 2, i.e., in particular when the control tube 4 is in the second relative position with respect to the catalyst 3, the exhaust gas A supplied to section 9a of the pressure reactor 9 via the exhaust pipe 2 flows into the control tube 4, passes through the catalyst 3, enters the second section 9b of the pressure reactor 9 via the recesses 16 of the control tube 4, and is discharged from the exhaust gas aftertreatment system 1 via the exhaust pipe 12.
[0036] Furthermore, the exhaust gas aftertreatment system 1 is equipped with a regenerating agent spraying device 17. The spraying device 17 is positioned adjacent to the inlet end of the catalyst 3, which is formed at the first axial end 10 of the catalyst 3, and can be supplied with the reaction agent released from the metering valve 18.
[0037] The spraying device 17 is preferably formed as a circular spray tube that can uniformly apply the regenerating agent to the inlet side of the catalyst 3 formed at the first axial end 10.
[0038] The actuator 6 of the exhaust gas aftertreatment system 1 in this embodiment includes a piston 19 that is actuated by a pressure medium, and this piston 19 is guided to move within a pressure medium cylinder 20. A piston rod 21, which is operatively connected to a second closure body 14, acts on the piston 19.
[0039] The pressure medium cylinder 20 is supplied with pressure medium from the pressure medium reservoir 22, and the pressure medium piston 19 and the control pipe 4 can be moved axially relative to the catalyst 3 via the pressure medium piston 19.
[0040] The exhaust gas aftertreatment system 1 further includes at least one sensor for detecting at least one operating condition of the engine and / or at least one operating condition of the exhaust gas aftertreatment system.
[0041] Accordingly, Figure 1 shows a sensor 23 located in the exhaust pipe 2, which is focused on, for example, detecting engine misfires. For this purpose, the sensor 23 can be designed as, for example, a temperature sensor, and in particular, can indicate a misfire in the engine when it detects that fuel has been burned in the engine and then a drop in temperature.
[0042] Furthermore, Figures 1 and 2 show a temperature sensor 24 for detecting the exhaust gas temperature of the exhaust gas flowing out of the catalyst 3, located in the region of the second part 9b of the pressure reactor 9.
[0043] Furthermore, the pressure sensor 25 shown in Figures 1 and 2 acts on the exhaust pipe 12 at a first measurement point upstream of the orifice plate 26 and a second measurement point downstream of the orifice plate 26.
[0044] Furthermore, the exhaust gas aftertreatment system 1 includes a control device that can control the actuator 6 as a function of at least one operating condition of the engine and / or at least one operating condition of the exhaust gas aftertreatment system in order to move the control pipe 4 to either the position shown in Figure 1 or the position shown in Figure 2.
[0045] Accordingly, the exhaust gas aftertreatment system of the present invention comprises a catalyst 3 preferably formed as an annular catalyst, a control tube 4 integrated with the catalyst 3 and movable in the axial direction relative to the control tube 4, and an actuator 6.
[0046] Preferably, the exhaust gas aftertreatment system 1 further includes a spray device 17 for a regenerating agent and at least one sensor 23, 24, 25.
[0047] The control tube 4 is movably positioned within the catalyst 3, specifically within the inner catalyst tube 7, and is axially movable via the actuator 6. Absolute tightness of the control components is not required. Effective exhaust gas aftertreatment can be ensured with minimal installation space.
[0048] The catalyst 3 has an annular cross-section and is equipped with a recess 5 through which the control pipe 4 is guided. The exhaust gas passes through the catalyst 3 and is transmitted through the control pipe 4. The exhaust gas guided through the control pipe 4 can preheat the catalyst 3 even before the exhaust gas has flowed through the control pipe 4 to the catalyst 3.
[0049] In particular, when starting the engine, a high concentration of ignitable residual gas of the gaseous fuel is present in the exhaust gas. Subsequently, these high-concentration portions can pass through the catalyst 3 without undergoing an oxidation reaction within the catalyst 3 and be transmitted via the control tube 4.
[0050] The control tube 4 is moved axially by the actuator 6. The movement of the control tube 4 may depend, for example, on exhaust gas pressure and / or exhaust gas temperature. Temperature and pressure can be detected by measuring them using sensors 24 and 25.
[0051] The control tube 4 supports the closure bodies 13 and 14. Depending on the relative position of the control tube 4 with respect to the catalyst 3, either the first closure body 13 or the second closure body 14 becomes effective.
[0052] The closure bodies 13 and 14 preferably have a conical shape. This conical shape of the closure bodies 13 and 14 ensures effective sealing at each closure position without requiring a separate seal.
[0053] The exhaust gas aftertreatment system 1 can be supplied with exhaust gas via the exhaust line 2. The purified exhaust gas can be discharged via the exhaust line 12. In the regeneration mode of the catalyst 3, the regenerator can be discharged from the exhaust gas aftertreatment system 1 via a further line 27.
[0054] To regenerate the catalyst 3, the exhaust gas aftertreatment system 1 is equipped with a spray device 17, which allows the regenerator to be applied to the catalyst 3 in the region of the first axial end 10, and therefore the region on the inlet side. In particular, the regeneration of the catalyst 3 is performed when no exhaust gas flows into the catalyst 3. This allows for effective regeneration of the catalyst 3 with a very small amount of regenerator. Regeneration can be performed within the catalyst 3 at low temperatures. Regeneration can also be performed with the engine stopped or under other operating conditions.
[0055] Catalyst 3 is preferably a methane catalyst. Ethanol, ethane, or nitrogen are suitable as regenerating agents.
[0056] Furthermore, the present invention relates to an engine equipped with the exhaust gas aftertreatment system 1 described above, and a method for operating the exhaust gas aftertreatment system 1.
[0057] In particular, when the control pipe 4 is in the first relative position in Figure 1, the exhaust gas is purified by the catalyst 3. Therefore, the control pipe 4 takes this first position in Figure 1 in catalytic mode, when gaseous fuel is burned in the engine. Then, exhaust gas A flows through the catalyst 3 and is discharged through the exhaust pipe 12. The temperature sensor 24 can detect, for example, the allowable exhaust gas temperature downstream of the exhaust gas catalyst 3. The pressure sensor 25 can detect the exhaust pressure downstream of the catalyst 3. Accordingly, the control pipe 4 can move from the relative position in Figure 1 to the relative position in Figure 2, which corresponds to the catalyst bypass mode, during which the exhaust gas is not transmitted through the catalyst 3, but rather passes through the catalyst 3 and is transmitted through the control pipe 4.
[0058] The control pipe 4 of the dual-fuel engine takes the relative position shown in Figure 2, especially when operating with liquid fuel, i.e., when diesel fuel is burned in the engine. The exhaust gas of the diesel fuel is not transmitted through the methane catalyst. Furthermore, the exhaust gas aftertreatment system, i.e., the control pipe 4 of the system, takes the relative position shown in Figure 2 during engine startup and / or engine shutdown and / or emergency operation and / or engine failure, such as misfire and / or exhaust gas overheating.
[0059] The present invention enables effective exhaust gas purification of gas engines or dual-fuel engines operating in gas-fuel mode, with minimal installation space requirements for the exhaust gas aftertreatment system 1. The exhaust gas aftertreatment system 1 according to the present invention can be easily retrofitted to existing engines. The catalyst 3 can be effectively regenerated with a minimal amount of regenerating agent.
Claims
1. An exhaust gas aftertreatment system (1) for an engine designed as a gas engine or a dual-fuel engine, A catalyst (3) through which exhaust gas can flow, A control tube (4) extending through a recess (5) of the catalyst (3), which can be moved relative to the catalyst (3) and through which exhaust gas can flow, An actuator (6) that can move the control tube (4) relative to the catalyst (3) in accordance with at least one operating condition of the engine and / or at least one operating condition of the exhaust gas aftertreatment system, Equipped with, At the first relative position of the control tube (4) with respect to the catalyst (3), exhaust gas can flow through the catalyst (3) but not through the control tube (4), and at the second relative position of the control tube (4) with respect to the catalyst (3), exhaust gas can flow through the control tube (4) but not through the catalyst (3). The control tube (4) supports a first closure body (13) in a first portion (4a), and the first closure body (13) allows the flow of exhaust gas through the catalyst (3) at the first relative position of the control tube (4), and obstructs the flow of exhaust gas through the catalyst (3) at the second relative position of the control tube (4). The control tube (4) supports a second closure body (14) in its second portion (4b), and the second closure body (14) seals the gap (15) between the control tube (4) and the catalyst (3) at the first relative position of the control tube (4). Exhaust gas aftertreatment system.
2. The exhaust gas aftertreatment system according to claim 1, characterized in that the catalyst (3) is an annular catalyst, the radially inner side of the catalyst (3) is defined by a first catalyst tube (7) in the region of a recess (5) that receives the control tube (4), the radially outer side of the catalyst (3) is defined by a second catalyst tube (8) and / or a pressure reactor (9), the first axial end (10) having an exhaust gas inlet side, and the second axial end (11) having an exhaust gas outlet side.
3. The exhaust gas aftertreatment system according to claim 1, characterized in that the control pipe (4) includes a third portion (4c) which is closed at the first relative position of the control pipe (4) and open at the second relative position of the control pipe (4).
4. The exhaust gas aftertreatment system according to claim 1, further comprising a spray device (17) for a regenerating agent, the regenerating agent can be introduced into the catalyst (3) via the spray device at the first relative position of the control tube (4) to the catalyst (3) and the second relative position of the control tube (4) to the catalyst (3).
5. The exhaust gas aftertreatment system according to claim 1, characterized by including at least one sensor (23, 24, 25) for detecting at least one operating condition of the engine and / or at least one operating condition of the exhaust gas aftertreatment system.
6. The exhaust gas aftertreatment system according to claim 1, characterized in that it includes a control device for controlling an actuator (6) depending on at least one operating condition of the engine and / or at least one operating condition of the exhaust gas aftertreatment system.
7. An engine having an exhaust gas aftertreatment system (1) according to any one of claims 1 to 6, i.e., a gas engine or a dual-fuel engine.
8. A method for operating the exhaust gas aftertreatment system (1) according to any one of claims 1 to 6, When gaseous fuel is burning in the engine, the control tube (4) moves to the first relative position with respect to the catalyst (3). When liquid fuel is burning in the engine, and / or when there is an engine malfunction, and / or when the engine is started, and / or when the engine is stopped, and / or when exhaust gas overheating occurs, and / or when the catalyst is regenerated, the control tube (4) moves to the second relative position with respect to the catalyst (3). method.