Catalytic converter system for exhaust gas aftertreatment

Abstract

The present disclosure relates to a catalytic converter system for the post-treatment of exhaust gases of an automobile. The catalytic converter system comprises: first and second exhaust pipes arranged in parallel; first and second catalytic converters installed respectively in the first and second exhaust pipes; a first exhaust valve installed in the first exhaust pipe and operated to open or close the first exhaust pipe; a second exhaust valve installed in the second exhaust pipe and operated to open or close the second exhaust pipe; a bypass passage connecting the first and second exhaust pipes to each other at the upstream end of the first and second catalytic converters; and a controller for controlling the operation of the first and second exhaust valves. The controller controls the operation of the first and second exhaust valves to open both the first and second exhaust pipes or to open one of the first and second exhaust pipes and close the other, based on the thermal conditions of the exhaust gases flowing through the first and second exhaust pipes.

Description

Technology Field

[0001] The present disclosure relates to a catalytic converter system for the post-treatment of exhaust gases from an automobile. Background Technology

[0002] Aftertreatment is performed to reduce harmful substances in exhaust gases emitted from automobile engines, and catalytic converters are used for exhaust gas aftertreatment. Catalytic converters purify harmful substances generated by incomplete combustion or unwanted reactions in the engine by utilizing chemical reactions by catalysts, and may be devices that reduce harmful substances in exhaust gases by using catalysts such as three-way catalytic converters, DOC (diesel oxidation catalyst) devices, and SCR (selective catalyst reduction) devices.

[0003] For the normal operation of a catalytic converter, the catalyst must be heated to an appropriate operating temperature. However, under conditions such as cold starts, where there is a lack of heat sources capable of rapidly heating the catalyst to the operating temperature, it takes a long time for the catalyst to reach this temperature. Consequently, unpurified exhaust gases are emitted, making it difficult to meet strict environmental regulations. Therefore, a solution is needed to ensure the stable operation of the catalytic converter even under conditions where it is difficult to rapidly heat the catalyst to the appropriate temperature.

[0004] The matters described in the technical background section of this invention are written to enhance understanding of the background of the invention and may include matters that are not prior art already known in the field to which this technology belongs. Prior art literature

[0005] Republic of Korea Registered Patent No. 10-2197385, Japanese Published Patent No. 2012-172633 The problem to be solved

[0006] The problem that the present invention aims to solve is to provide a catalytic converter system capable of effectively reducing harmful substances even under conditions where the heat source of the exhaust gas is insufficient to rapidly heat the catalyst to the operating temperature.

[0007] The technical problems that the present invention aims to solve are not limited to those mentioned above, and other technical problems not mentioned will be understood by those skilled in the art from the description below. means of solving the problem

[0008] A catalytic converter system according to one embodiment of the present invention comprises: first and second exhaust pipes arranged in parallel; first and second catalytic converters installed respectively in the first and second exhaust pipes; a first exhaust valve installed in the first exhaust pipe and operated to open or close the first exhaust pipe; a second exhaust valve installed in the second exhaust pipe and operated to open or close the second exhaust pipe; a bypass passage connecting the first and second exhaust pipes to each other at the front end of the first and second catalytic converters; and a controller for controlling the operation of the first and second exhaust valves. The controller controls the operation of the first and second exhaust valves to open both the first and second exhaust pipes or to open one of the first and second exhaust pipes and close the other, based on the thermal conditions of the exhaust gas flowing through the first and second exhaust pipes.

[0009] The controller may control the operation of the first and second exhaust valves to open one of the first and second exhaust pipes and close the other when the thermal conditions of the exhaust gas are not in a state where both the first and second catalytic converters can be heated to a preset temperature within a preset time. When either of the first and second exhaust pipes is closed by either of the first and second exhaust valves, the exhaust gas may be configured to move through the bypass passage toward the unclosed of the first and second exhaust pipes.

[0010] The above bypass passage can connect the first and second exhaust pipes to each other at the upstream end of the first and second exhaust valves.

[0011] In one embodiment of the present invention, the first and second exhaust valves may be installed to be located at the front of the first and second catalytic converters, respectively.

[0012] Meanwhile, in another embodiment of the present invention, the first and second exhaust valves may be installed to be located at the downstream ends of the first and second catalytic converters, respectively.

[0013] The above controller can control the first exhaust valve and the second exhaust valve to alternately close at a preset cycle.

[0014] A catalytic converter system according to another embodiment of the present invention comprises: an exhaust pipe configured to allow exhaust gas to flow; a catalytic converter installed in the exhaust pipe; a partition wall that partitions the inner space of the exhaust pipe at the front end of the catalytic converter to form first and second exhaust gas passages; a first exhaust valve installed in the first exhaust gas passage and operated to open or close the first exhaust passage; a second exhaust valve installed in the second exhaust gas passage and operated to open or close the second exhaust passage; and a controller that controls the operation of the first and second exhaust valves. The controller controls the operation of the first and second exhaust valves based on the thermal conditions of the exhaust gas flowing through the exhaust pipe to open both the first and second exhaust gas passages, or to open one of the first and second exhaust gas passages and close the other.

[0015] The controller can control the operation of the first and second exhaust valves to open one of the first and second exhaust gas passages and close the other when the thermal conditions of the exhaust gas are not in a state where the entire catalytic converter can be heated to a preset temperature within a preset time.

[0016] The catalytic converter may be an SCR device. In this case, the catalytic converter system may further include a urea injector installed upstream of the bulkhead and configured to inject urea into the exhaust gas flowing through the exhaust pipe; and a mixer for mixing the injected urea and the exhaust gas.

[0017] A catalytic converter system according to another embodiment of the present invention comprises: an exhaust pipe configured to allow exhaust gas to flow; a catalytic converter installed in the exhaust pipe; a front partition wall that partitions the inner space of the exhaust pipe at the front end of the catalytic converter to form first and second front exhaust gas passages; a rear partition wall that partitions the inner space of the exhaust pipe at the rear end of the catalytic converter to form first and second rear exhaust gas passages; a first exhaust valve installed in the first rear exhaust gas passage and operated to open or close the first rear exhaust passage; a second exhaust valve installed in the second rear exhaust gas passage and operated to open or close the second rear exhaust passage; and a controller that controls the operation of the first and second exhaust valves. The controller controls the operation of the first and second exhaust valves based on the thermal conditions of the exhaust gas flowing through the exhaust pipe to either open both the first and second downstream exhaust gas passages or open one of the first and second downstream exhaust gas passages and close the other. Effects of the invention

[0018] According to the present invention, in the event that the exhaust gas does not possess sufficient heat to rapidly heat the catalytic converter to an operating temperature, the exhaust gas is introduced into a part of a plurality of catalytic converters or into a part of a catalytic converter, thereby enabling the catalytic converter to be rapidly heated to an operating temperature and, consequently, effective removal of harmful substances is possible even under conditions where heat sources are insufficient, such as during a cold start. Brief explanation of the drawing

[0019] FIG. 1 is a drawing showing a state in which one of two exhaust valves is closed in a catalytic converter system according to an embodiment of the present invention. FIG. 2 is a drawing showing a state in which both exhaust valves are open in a catalytic converter system according to an embodiment of the present invention. FIG. 3 illustrates a schematic block diagram of a catalytic converter system according to an embodiment of the present invention. FIG. 4 is a drawing showing a state in which one of the two exhaust valves is closed in a catalytic converter system according to another embodiment of the present invention. FIG. 5 is a drawing showing a state in which both exhaust valves are open in a catalytic converter system according to another embodiment of the present invention. FIG. 6 is a drawing showing a state in which one of the two exhaust valves is closed in a catalytic converter system according to another embodiment of the present invention. FIG. 7 is a drawing showing a state in which both exhaust valves are open in a catalytic converter system according to another embodiment of the present invention. FIG. 8 is a drawing showing a state in which one of the two exhaust valves is closed in a catalytic converter system according to another embodiment of the present invention. FIG. 9 is a drawing showing a state in which both exhaust valves are open in a catalytic converter system according to another embodiment of the present invention. FIG. 10 is a drawing showing a state in which one of two exhaust valves is closed in a catalytic converter system according to another embodiment of the present invention. FIG. 11 is a drawing showing a state in which both exhaust valves are open in a catalytic converter system according to another embodiment of the present invention. Specific details for implementing the invention

[0020] Embodiments of the present invention are described below with reference to the attached drawings so that those skilled in the art can easily implement the invention. However, the present invention may be embodied in various different forms and is not limited to the described embodiments.

[0021] The terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the invention. As used herein, the singular form is intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising” and / or “comprising” as used herein indicate the presence of the specified features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, components, and / or groups thereof. As used herein, the term “and / or” includes any one or all combinations of one or more items listed in association. The term “combined” indicates a physical relationship between two components where the components are directly connected to each other or indirectly connected through one or more mediating components.

[0022] In describing the components of the present invention, where it is stated that one component is "connected," "coupled," or "connected" to another component, it should be understood that the component may be directly connected, coupled, or connected to the other component, but that another component may also be "connected," "coupled," or "connected" between each component.

[0023] FIG. 1 is a diagram showing the state of a catalytic converter system according to an embodiment of the present invention under low-load conditions, and FIG. 2 is a diagram showing the state of a catalytic converter system according to an embodiment of the present invention under high-load conditions. FIG. 3 illustrates a schematic block diagram of a catalytic converter system according to an embodiment of the present invention. FIG. 1 and FIG. 2 illustrate an exemplary case in which a catalytic converter system (10) according to an embodiment of the present invention is installed in first and second exhaust pipes (101, 102) configured to allow exhaust gas to flow through them, connected to an engine of a vehicle, for example, a diesel engine (not shown). FIG. 1 and FIG. 2 illustrate an example in which two exhaust pipes (101, 102) are provided and arranged in parallel, in which case the exhaust pipes (101, 102) are connected to each bank of a V-type engine, thereby allowing exhaust gas discharged from the cylinder to flow through the exhaust pipes (101, 102). The catalytic converter system (10) includes first and second catalytic converters (11, 12) respectively disposed in exhaust pipes (101, 102). The first and second catalytic converters (11, 12) may be devices that reduce harmful substances in exhaust gas using catalysts such as a three-way catalytic converter, a DOC (diesel oxidation catalyst) device, or an SCR (selective catalyst reduction) device.

[0024] As illustrated in FIGS. 1 and 2, the first and second exhaust valves (13, 14) are respectively installed in the exhaust pipes (101, 102) so as to be located upstream of the first and second catalytic converters (11, 12). The first and second exhaust valves (13, 14) are configured to open or close the first and second exhaust pipes (101, 102). Referring to FIG. 3, a controller (15) controls the operation of the first and second exhaust valves (13, 14), and the first and second exhaust valves (13, 14) are operated by a control signal from the controller (15) to open or close the exhaust pipes (101, 102). For example, the first exhaust valve (13) may include a valve plate (131) rotatably disposed within the first exhaust pipe (101), a rotating shaft (132) connected to the valve plate (131), and an actuator (133) providing driving force to rotate the rotating shaft (132). The valve plate (131) may have a circular plate shape, and the actuator (133) may be a motor that generates driving force. Similarly, the second exhaust valve (14) may include a valve plate (141) rotatably disposed within the second exhaust pipe (102), a rotating shaft (142) connected to the valve plate (141), and an actuator (143) providing driving force to rotate the rotating shaft (142).

[0025] The bypass passage (103) connects the first and second exhaust pipes (101, 102) to each other at the front of the first and second exhaust valves (13, 14). When either of the first and second exhaust valves (13, 14) is in a position to close the exhaust pipe (101, 102), the exhaust gas from the closed exhaust pipe moves to the other exhaust pipe through the bypass passage (103). For example, as shown in FIG. 1, when the second exhaust valve (14) closes the second exhaust pipe (102), the exhaust gas flowing through the second exhaust pipe (102) moves to the first exhaust pipe (101) through the bypass passage (103) along the direction indicated by the arrow, joins with the exhaust gas flowing through the first exhaust pipe (101), and then passes through the first catalytic converter (11). In contrast, when the first exhaust valve (13) closes the first exhaust pipe (101) and the second exhaust valve (14) opens the second exhaust pipe (102), the exhaust gas flowing through the first exhaust pipe (101) moves to the second exhaust pipe (102) through the bypass passage (103), joins with the exhaust gas flowing through the second exhaust pipe (102), and then passes through the second catalytic converter (12). Meanwhile, as shown in FIG. 2, when the first exhaust valve (13) opens the first exhaust pipe (101) and the second exhaust valve (14) opens the second exhaust pipe (102), the exhaust gas flowing through the first exhaust pipe (101) passes through the first catalytic converter (11) and is discharged, and the exhaust gas flowing through the second exhaust pipe (102) passes through the second catalytic converter (12) and is discharged.

[0026] The controller (15) controls the operation of the first and second exhaust valves (13, 14) according to the thermal conditions of the exhaust gas. For example, the controller (15) can control the operation of the first and second exhaust valves (13, 14) by controlling the actuators (133, 143). The controller (15) may include a microprocessor, memory, and related hardware and software, and may be programmed to control the operation of the first and second exhaust valves (13, 14) according to the exhaust gas condition. When the thermal conditions of the exhaust gas satisfy the conditions for normal operation of the first and second catalytic converters (11, 12), the controller (15) controls the first and second exhaust valves (13, 14) to open so that the exhaust gas passes through the first and second catalytic converters (11, 12). Meanwhile, if the exhaust gas condition does not meet the conditions for normal operation of the first and second catalytic converters (11, 12), the controller (15) controls one of the first and second exhaust valves (13, 14) to be closed so that the exhaust gas passes through either of the first and second catalytic converters (11, 12). In this regard, the thermal condition of the exhaust gas includes conditions that allow the exhaust gas to rapidly heat the first and second catalytic converters (11, 12) to an operating temperature, and may include, for example, the flow rate and temperature of the exhaust gas. The thermal condition of the exhaust gas can be evaluated based on the flow rate and temperature of the exhaust gas, and it can be determined whether the catalytic converters (11, 12) can be rapidly heated to an operating temperature within a set time based on the combination of the flow rate and temperature of the exhaust gas. Whether such thermal conditions are satisfied may be determined experimentally or calculated theoretically. Information on the flow rate and temperature of exhaust gases may be received by an engine control unit (not shown) and may also be received via a separate sensor.

[0027] The controller (15) can control the opening and closing of the first and second exhaust valves (13, 14) based on one or more of the flow rate and temperature of the exhaust gas, depending on whether the exhaust gas at that time can heat the two catalytic converters (11, 12) to a temperature at which normal operation is possible within a set time. For example, if it is determined that the condition for heating the two catalytic converters (11, 12) to a set temperature within a set time for normal operation of the two catalytic converters (11, 12) is satisfied based on the flow rate and temperature of the exhaust gas (e.g., high-speed high-load condition), the controller (15) opens both the first and second exhaust valves (13, 14). Under these normal exhaust gas conditions, the exhaust gas can be seen as having a heat source capable of rapidly heating two catalytic converters (11, 12) to an operating temperature, and in this case, the exhaust gas is discharged after passing through two first and second catalytic converters (11, 12) in which the separated exhaust pipes (101, 102) are respectively arranged.

[0028] In contrast, if it is determined that conditions for heating the two catalytic converters (11, 12) to a predetermined temperature within a predetermined time for normal operation of the two catalytic converters (11, 12) based on the flow rate and temperature of the exhaust gas are not met (e.g., low speed, low load conditions), the controller (15) opens one of the first and second exhaust valves (13, 14) and closes the other. If it is determined that the flow rate of the exhaust gas at a specific point in time is small or the temperature of the exhaust gas is low, making it difficult for the two catalytic converters (11, 12) to be heated quickly to a normal operating state simultaneously within a predetermined time by the heat of the exhaust gas, one of the first and second exhaust valves (13, 14) is closed so that the exhaust gas flows into either of the first and second catalytic converters (11, 12), thereby allowing the catalytic converter through which the exhaust gas flows to be heated to a predetermined temperature within a shorter time. Through this control, in cases where it is difficult for the two catalytic converters (11, 12) to be heated to a normal operating state by the exhaust gas under conditions such as cold start in a low-speed, low-load state, the exhaust gas is allowed to flow entirely into either of the two catalytic converters (11, 12), thereby preventing the emission of exhaust gas in which harmful substances are not sufficiently reduced.

[0029] FIG. 1 illustrates a case where the first exhaust valve (13) is open and the second exhaust valve (14) is closed, but alternatively, the first exhaust valve (13) may be closed and the second exhaust valve (14) may be open. As described above, if it is necessary to use only one of the two catalytic converters (11, 12) for exhaust gas, the two catalytic converters (11, 12) may be used alternately to prevent continuous use of only one catalytic converter. For example, the first catalytic converter (11) may be used for a set engine operating time, e.g., 100 hours, and the second catalytic converter (12) may be used for the subsequent 100 hours. By using the two catalytic converters (11, 12) alternately in this way, the shortening of the lifespan of a single catalytic converter due to continuous use can be prevented.

[0030] FIG. 4 is a drawing showing a state in which one of two exhaust valves is closed in a catalytic converter system according to another embodiment of the present invention, and FIG. 5 is a drawing showing a state in which both exhaust valves are open in a catalytic converter system according to another embodiment of the present invention.

[0031] As illustrated in FIGS. 4 and 5, the first and second exhaust valves (53, 54) are respectively installed in the exhaust pipes (501, 502) so as to be located at the rear ends of the first and second catalytic converters (51, 52). The first and second exhaust valves (53, 54) are configured to open or close the first and second exhaust pipes (501, 502). For example, the first exhaust valve (53) may include a valve plate (531) rotatably disposed within the first exhaust pipe (501), a rotating shaft (532) connected to the valve plate (531), and an actuator (533) providing driving force to rotate the rotating shaft (532). The valve plate (531) may have a circular plate shape, and the actuator (533) may be a motor that generates driving force. Similarly, the second exhaust valve (54) may include a valve plate (541) rotatably disposed within the second exhaust pipe (502), a rotating shaft (542) connected to the valve plate (541), and an actuator (543) providing a driving force to rotate the rotating shaft (542).

[0032] The bypass passage (503) connects the first and second exhaust pipes (501, 502) to each other at the front of the first and second catalytic converters (51, 53). When either of the first and second exhaust valves (53, 54) is in a position to close the exhaust pipe (501, 502), the exhaust gas from the closed exhaust pipe moves to the other exhaust pipe through the bypass passage (503). For example, as shown in FIG. 4, when the second exhaust valve (54) closes the second exhaust pipe (502), the exhaust gas flowing through the second exhaust pipe (502) moves to the first exhaust pipe (501) through the bypass passage (503) along the direction indicated by the arrow, joins with the exhaust gas flowing through the first exhaust pipe (501), and then passes through the first catalytic converter (51). In contrast, when the first exhaust valve (53) closes the first exhaust pipe (501) and the second exhaust valve (54) opens the second exhaust pipe (502), the exhaust gas flowing through the first exhaust pipe (501) moves to the second exhaust pipe (502) through the bypass passage (503), joins with the exhaust gas flowing through the second exhaust pipe (502), and then passes through the second catalytic converter (52). Meanwhile, as shown in FIG. 5, when the first exhaust valve (53) opens the first exhaust pipe (501) and the second exhaust valve (54) opens the second exhaust pipe (502), the exhaust gas flowing through the first exhaust pipe (501) passes through the first catalytic converter (51) and is discharged, and the exhaust gas flowing through the second exhaust pipe (502) passes through the second catalytic converter (52) and is discharged. The first and second exhaust valves (53, 54) can be controlled by a controller in the same way as in the embodiment described above.

[0033] FIG. 6 is a drawing showing a state in which one of two exhaust valves is closed in a catalytic converter system according to another embodiment of the present invention, and FIG. 7 is a drawing showing a state in which both exhaust valves are open in a catalytic converter system according to another embodiment of the present invention. The catalytic converter system (20) illustrated in FIG. 6 and FIG. 7 is applied to an exhaust system having a single exhaust pipe (201), such as a serial engine.

[0034] The catalytic converter system (20) includes a catalytic converter (21) installed in an exhaust pipe (201). A partition (25) is installed within the exhaust pipe (201) such that it is located at the front end of the catalytic converter (21). The partition (25) divides the internal space of the exhaust pipe (201) at the front end of the catalytic converter (21) to form first and second exhaust gas passages (203, 204) that are separated from each other. Accordingly, some of the exhaust gas flows into one part of the catalytic converter (21) through the first exhaust gas passage (203), and the remaining part of the exhaust gas flows into the remaining part of the catalytic converter (21) through the second exhaust gas passage (204).

[0035] First and second exhaust valves (23, 24) are provided to selectively open and close the first and second exhaust gas passages (203, 204). The first exhaust valve (23) may include a valve plate (231) rotatably disposed in the first exhaust gas passage (203), a rotating shaft (232) connected to the valve plate (231), and an actuator (233) providing a driving force to rotate the rotating shaft (232). Similarly, the second exhaust valve (24) may include a valve plate (241) rotatably disposed in the second exhaust gas passage (204), a rotating shaft (242) connected to the valve plate (241), and an actuator (243) providing a driving force to rotate the rotating shaft (242).

[0036] Similar to the embodiment described above, a controller (not shown) controls the operation of the first and second exhaust valves (23, 24) according to the exhaust gas condition. If, based on the flow rate and temperature of the exhaust gas, it is determined that the current exhaust gas cannot heat the entire catalytic converter (21) to a predetermined temperature within a predetermined time, one of the first and second exhaust valves (23, 24) is closed as shown in FIG. 6 so that the exhaust gas flows into a part of the catalytic converter (21) along the direction of the arrow. Conversely, if it is determined that the current exhaust gas can heat the entire catalytic converter (21) to a predetermined temperature within a predetermined time, both the first and second exhaust valves (23, 24) are opened as shown in FIG. 7 so that the exhaust gas flows into the entire catalytic converter (21). Accordingly, under normal conditions, exhaust gas is introduced into the entire catalytic converter (21) to reduce harmful substances, and under conditions such as cold start in a low-speed, low-load state, exhaust gas is introduced into a part of the catalytic converter (21) so that the corresponding part of the catalytic converter (21) can operate normally. In such cases, where it is difficult for the entire catalytic converter (21) to be rapidly heated to the operating temperature by the heat of the exhaust gas, such as under low-speed, low-load conditions, the reduction of harmful substances in the exhaust gas can be achieved normally by allowing the exhaust gas to be introduced into a part of the catalytic converter (21) through the operation of the first and second exhaust valves (23, 24). In this regard, when using a part of the catalytic converter (21), the first and second exhaust valves (23, 24) can be alternately closed at a set engine operating time interval so that both sides of the catalytic converter (21) can be used alternately.

[0037] FIG. 8 is a drawing showing one of two exhaust valves in a closed state in a catalytic converter system according to another embodiment of the present invention, and FIG. 9 is a drawing showing both exhaust valves in an open state in a catalytic converter system according to another embodiment of the present invention. The catalytic converter system (30) illustrated in FIG. 8 and FIG. 9 is applied to an exhaust system having a single exhaust pipe (301), such as a serial engine.

[0038] The catalytic converter system (30) includes a catalytic converter (31) installed in an exhaust pipe (301). A first partition (35) is installed in the exhaust pipe (201) so as to be located at the front end of the catalytic converter (31), and a second partition (36) is installed in the exhaust pipe (201) so as to be located at the rear end of the catalytic converter (31). The first partition (35) partitions the internal space of the exhaust pipe (301) at the front end of the catalytic converter (31) to form first and second front exhaust gas passages (303, 304) separated from each other, and the second partition (36) partitions the internal space of the exhaust pipe (301) at the rear end of the catalytic converter (31) to form first and second rear exhaust gas passages (305, 306) separated from each other. Accordingly, some of the exhaust gas flows into a part of the catalytic converter (31) through the first front exhaust gas passage (303), and the remaining part of the exhaust gas flows into the remaining part of the catalytic converter (31) through the second front exhaust gas passage (304). At this time, the first partition (35) and the second partition (36) can be formed at corresponding positions, so that the exhaust gas flowing into the catalytic converter (31) through the first front exhaust gas passage (303) is mainly discharged through the first rear exhaust gas passage (305), and the exhaust gas flowing into the catalytic converter (31) through the second front exhaust gas passage (304) is mainly discharged through the second rear exhaust gas passage (306).

[0039] First and second exhaust valves (33, 34) are provided to selectively open and close the first and second rear exhaust gas passages (305, 306). The first exhaust valve (33) may include a valve plate (331) rotatably disposed in the first rear exhaust gas passage (305), a rotating shaft (332) connected to the valve plate (331), and an actuator (333) providing a driving force to rotate the rotating shaft (332). Similarly, the second exhaust valve (34) may include a valve plate (341) rotatably disposed in the second rear exhaust gas passage (306), a rotating shaft (342) connected to the valve plate (341), and an actuator (343) providing a driving force to rotate the rotating shaft (342).

[0040] Similar to the embodiment described above, a controller (not shown) controls the operation of the first and second exhaust valves (33, 34) according to the exhaust gas condition. If, based on the flow rate and temperature of the exhaust gas, it is determined that the current exhaust gas is difficult to heat the entire catalytic converter (31) to a predetermined temperature within a predetermined time, one of the first and second exhaust valves (33, 34) is closed as shown in FIG. 8 so that the exhaust gas flows into a part of the catalytic converter (31). That is, referring to FIG. 8, when the second exhaust valve (34) is closed, the flow of exhaust gas flowing into the right part of the catalytic converter (31) is stagnated, and the flow of exhaust gas into the second front exhaust gas passage (304) is blocked and flows into the first front exhaust gas passage (303). Accordingly, exhaust gas is introduced into the left side of the catalytic converter (31) through the first front exhaust gas passage (303) and then discharged through the first rear exhaust gas passage (305). At this time, the first exhaust valve (33) may be closed instead of the second exhaust valve (34). Alternatively, if it is determined that the exhaust gas can heat the entire catalytic converter (31) to a predetermined temperature within a predetermined time, both the first and second exhaust valves (33, 34) are opened as shown in FIG. 9 to allow the exhaust gas to flow into the entire catalytic converter (31). In this way, under normal conditions, the exhaust gas flows into the entire catalytic converter (31) to reduce harmful substances, and under conditions such as cold start in a low-speed, low-load state, the exhaust gas flows into a part of the catalytic converter (31) to allow that part of the catalytic converter (31) to operate normally. In cases where it is difficult to rapidly heat the entire catalytic converter (31) to the operating temperature by the heat of the exhaust gas, such as under low speed and low load conditions, the reduction of harmful substances in the exhaust gas can be achieved normally by allowing the exhaust gas to flow into a part of the catalytic converter (31) through the operation of the first and second exhaust valves (33, 34).In this regard, when using a part of the catalytic converter (31), the first and second exhaust valves (33, 34) can be alternately closed at a set engine operating time interval so that both sides of the catalytic converter (31) are alternately used.

[0041] FIG. 10 is a drawing showing a state in which one of two exhaust valves is closed in a catalytic converter system according to another embodiment of the present invention, and FIG. 11 is a drawing showing a state in which both exhaust valves are open in a catalytic converter system according to another embodiment of the present invention. The catalytic converter system (40) illustrated in FIG. 10 and FIG. 11 is applied to an exhaust system having a single exhaust pipe (401), such as a serial engine.

[0042] The catalytic converter system (40) includes a catalytic converter (41) installed in an exhaust pipe (401). A partition (45) is installed within the exhaust pipe (401) such that it is located at the front end of the catalytic converter (41). The partition (45) divides the internal space of the exhaust pipe (401) at the front end of the catalytic converter (41) to form first and second exhaust gas passages (403, 404) that are separated from each other. Accordingly, some of the exhaust gas flows into one part of the catalytic converter (41) through the first exhaust gas passage (403), and the remaining part of the exhaust gas flows into the remaining part of the catalytic converter (41) through the second exhaust gas passage (404).

[0043] First and second exhaust valves (43, 44) are provided to selectively open and close the first and second exhaust gas passages (403, 404). The first exhaust valve (43) may include a valve plate (431) rotatably disposed in the first exhaust gas passage (403), a rotating shaft (432) connected to the valve plate (431), and an actuator (433) providing a driving force to rotate the rotating shaft (432). Similarly, the second exhaust valve (44) may include a valve plate (441) rotatably disposed in the second exhaust gas passage (404), a rotating shaft (442) connected to the valve plate (441), and an actuator (443) providing a driving force to rotate the rotating shaft (442). The catalytic converter (41) may be an SCR catalytic device using a reducing agent, and a urea injector (47) for injecting urea solution, which is a reducing agent, into the exhaust gas, and a mixer (48) for mixing the urea solution and the exhaust gas may be provided at the top of the partition (45).

[0044] Similar to the embodiment described above, a controller (not shown) controls the operation of the first and second exhaust valves (43, 44) according to the exhaust gas condition. If, based on the flow rate and temperature of the exhaust gas, it is determined that the current exhaust gas cannot heat the entire catalytic converter (41) to a predetermined temperature within a predetermined time, one of the first and second exhaust valves (43, 44) is closed as shown in FIG. 10 so that the exhaust gas flows into a part of the catalytic converter (41) along the direction indicated by the arrow. Conversely, if it is determined that the exhaust gas can heat the entire catalytic converter (41) to a predetermined temperature within a predetermined time, both the first and second exhaust valves (43, 44) are opened as shown in FIG. 11 so that the exhaust gas flows into the entire catalytic converter (41). Accordingly, under normal conditions, exhaust gas is introduced into the entire catalytic converter (41) to reduce harmful substances, and under conditions such as cold start in a low-speed, low-load state, exhaust gas is introduced into a part of the catalytic converter (41) so that the corresponding part of the catalytic converter (41) can operate normally. In such cases, where it is difficult to rapidly heat the entire catalytic converter (21) to the operating temperature by the heat of the exhaust gas, such as under low-speed, low-load conditions, the reduction of harmful substances in the exhaust gas can be achieved normally by allowing the exhaust gas to be introduced into a part of the catalytic converter (21) through the operation of the first and second exhaust valves (43, 44). In this regard, when using a part of the catalytic converter (41), the first and second exhaust valves (43, 44) can be alternately closed at a set engine operating time interval so that both sides of the catalytic converter (41) can be used alternately.

[0045] Although embodiments of the present invention have been described above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims also fall within the scope of the present invention. Explanation of the symbols

[0046] 10: Catalytic converter system 11, 12: Catalytic converter 13, 14: Exhaust valve 15: Controller 101, 102: Exhaust pipe

Claims

Claim 1 First and second exhaust pipes arranged in parallel; first and second catalytic converters installed respectively in the first and second exhaust pipes; a first exhaust valve installed in the first exhaust pipe and operated to open or close the first exhaust pipe; a second exhaust valve installed in the second exhaust pipe and operated to open or close the second exhaust pipe; a bypass passage connecting the first and second exhaust pipes to each other at the front end of the first and second catalytic converters; A catalytic converter system comprising a controller that controls the operation of the first and second exhaust valves, wherein the controller controls the operation of the first and second exhaust valves to open both the first and second exhaust pipes or to open one of the first and second exhaust pipes and close the other, based on the thermal conditions of the exhaust gas flowing through the first and second exhaust pipes, and wherein the controller controls the operation of the first and second exhaust valves to open one of the first and second exhaust pipes and close the other when the thermal conditions of the exhaust gas are not in a state where both the first and second catalytic converters can be heated to a preset temperature within a preset time, and wherein, when either of the first and second exhaust pipes is closed by either of the first and second exhaust valves, the exhaust gas is configured to move to the unclosed side of the first and second exhaust pipes through the bypass passage. Claim 2 delete Claim 3 In claim 1, the bypass passage is a catalytic converter system that connects the first and second exhaust pipes to each other at the front end of the first and second exhaust valves. Claim 4 A catalytic converter system according to claim 1, wherein the first and second exhaust valves are installed to be located at the front of the first and second catalytic converters, respectively. Claim 5 A catalytic converter system according to claim 1, wherein the first and second exhaust valves are installed to be located at the downstream ends of the first and second catalytic converters, respectively. Claim 6 In claim 1, the catalytic converter system wherein the controller controls the first exhaust valve and the second exhaust valve to alternately close at a preset period. Claim 7 An exhaust pipe configured to allow exhaust gas to flow; a catalytic converter installed in the exhaust pipe; a partition wall that partitions the inner space of the exhaust pipe at the front end of the catalytic converter to form first and second exhaust gas passages; a first exhaust valve installed in the first exhaust gas passage and operated to open or close the first exhaust passage; and a second exhaust valve installed in the second exhaust gas passage and operated to open or close the second exhaust passage. A catalytic converter system comprising a controller that controls the operation of the first and second exhaust valves, wherein the controller controls the operation of the first and second exhaust valves to open both the first and second exhaust gas passages or to open one of the first and second exhaust gas passages and close the other, based on the thermal conditions of the exhaust gas flowing through the exhaust pipe, and wherein the controller controls the operation of the first and second exhaust valves to open one of the first and second exhaust gas passages and close the other when the thermal conditions of the exhaust gas are not in a state where the entire catalytic converter can be heated to a preset temperature within a preset time. Claim 8 delete Claim 9 In claim 7, the catalyst converter is an SCR device, and the catalyst converter system further comprises: a urea injector installed at the front end of the bulkhead and configured to inject urea into the exhaust gas flowing through the exhaust pipe; and a mixer for mixing the injected urea and the exhaust gas. Claim 10 An exhaust pipe configured to allow exhaust gas to flow; a catalytic converter installed in the exhaust pipe; a front partition wall that partitions the inner space of the exhaust pipe at the front end of the catalytic converter to form first and second front exhaust gas passages; a rear partition wall that partitions the inner space of the exhaust pipe at the rear end of the catalytic converter to form first and second rear exhaust gas passages; a first exhaust valve installed in the first rear exhaust gas passage and operated to open or close the first rear exhaust gas passage; and a second exhaust valve installed in the second rear exhaust gas passage and operated to open or close the second rear exhaust gas passage. A catalytic converter system comprising a controller that controls the operation of the first and second exhaust valves, wherein the controller controls the operation of the first and second exhaust valves to open both the first and second exhaust gas passages or to open one of the first and second exhaust gas passages and close the other, based on the thermal conditions of the exhaust gas flowing through the exhaust pipe, and wherein the controller controls the operation of the first and second exhaust valves to open one of the first and second exhaust gas passages and close the other when the thermal conditions of the exhaust gas are not in a state where the entire catalytic converter can be heated to a preset temperature within a preset time.

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