JP2024022736A - Flow passage control device and flow passage control method for co2 storage in vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To contribute to extension of a service life of a CO₂ separation membrane.

SOLUTION: A control device (100) includes a processing unit for controlling to guide an exhaust gas from an internal combustion engine (11) mounted on a vehicle to a first flow passage (16) or a second flow passage (17). CO₂ in the exhaust gas guided into the first flow passage is supplied to a CO₂ storage device (40) in the vehicle through a CO₂ separation membrane (30). The processing unit controls to guide the exhaust gas to the first flow passage or the second flow passage in correspondence with concentration of an object substance contained in the exhaust gas.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a flow path control device and flow path control method for storing _CO2 in a vehicle.

Research has been conducted on technology to store CO ₂ in exhaust gas generated by the operation of a vehicle's internal combustion engine in a CO ₂ storage device installed inside the vehicle without emitting it outside the vehicle (for example, see Patent Document 1 below). .

Japanese Patent Application Publication No. 2007-177684

However, the concentration of CO ₂ in the exhaust gas is not so high, and it cannot be said that the capacity of the CO ₂ storage device is fully utilized. By increasing the concentration of CO ₂ in the gas supplied to the CO ₂ storage device, the capacity of the CO ₂ storage device can be fully utilized. For this reason, a method is being considered in which CO ₂ is separated from the exhaust gas by supplying the exhaust gas from the internal combustion engine to a CO ₂ separation membrane, and the separated CO ₂ is supplied to a CO ₂ storage device.

However, the exhaust gas may contain substances that promote deterioration of the CO ₂ separation membrane, and simply constantly supplying the exhaust gas to the CO ₂ separation membrane is not desirable for extending the life of the CO ₂ separation membrane.

An object of the present invention is to provide a flow path control device and a flow path control method for storing _CO2 in a vehicle, which contribute to extending the life of a _CO2 separation membrane.

A flow path control device for CO ₂ storage in a vehicle according to the present invention includes a processing section that controls guiding exhaust gas from an internal combustion engine mounted on a vehicle to a first flow path or a second flow path, and The CO ₂ in the exhaust gas guided to the flow path is supplied to the CO ₂ storage device in the vehicle through a CO ₂ separation membrane, and the processing unit controls the exhaust gas according to the concentration of the target substance contained in the exhaust gas. control is performed to guide the flow path to the first flow path or the second flow path.

According to the present invention, it is possible to provide a flow path control device and a flow path control method for storing CO ₂ in a vehicle, which contribute to extending the life of a CO ₂ separation membrane.

1 is a schematic plan view of a vehicle according to an embodiment of the present invention. FIG. 3 is a diagram showing the flow of exhaust gas when storage control is performed according to an embodiment of the present invention. FIG. 3 is a diagram showing the flow of exhaust gas when direct exhaust control is performed according to an embodiment of the present invention. FIG. 2 is an explanatory diagram of the structure and operation of a flow path switching device according to an embodiment of the present invention. 1 is a configuration diagram of a control device and a group of in-vehicle sensors according to an embodiment of the present invention. FIG. FIG. 7 is a diagram illustrating a procedure for creating and operating a trained model related to estimating the concentration of a target substance according to a fourth example belonging to an embodiment of the present invention. It is an operation flowchart related to switching between storage control and direct discharge control according to a sixth example belonging to the embodiment of the present invention. It is a functional block diagram of a control device according to an eighth example belonging to an embodiment of the present invention.

Examples of embodiments of the present invention will be specifically described below with reference to the drawings. In each referenced figure, the same parts are given the same reference numerals, and overlapping explanations regarding the same parts will be omitted in principle. In this specification, for the purpose of simplifying the description, symbols or codes that refer to information, signals, physical quantities, functional units, circuits, elements, parts, etc. are indicated, and information, signals, or codes corresponding to the symbols or codes are indicated. Names of physical quantities, functional units, circuits, elements, parts, etc. may be omitted or abbreviated.

FIG. 1 is a schematic plan view of a vehicle 1 according to this embodiment. The vehicle 1 is equipped with a CO ₂ recovery system. _CO2 refers to carbon dioxide. The vehicle 1 is, for example, a car that can run on a road surface, but the type of vehicle 1 is arbitrary.

The vehicle 1 includes an internal combustion engine 11, an exhaust manifold 12, an exhaust pipe 13, a purification device 14, a flow path switching device 15, a storage connection path 16, an exhaust connection path 17, a separation gas path 18, a residual gas discharge path 19, A muffler 20, a CO ₂ separation membrane 30, a CO ₂ storage device 40, a control device 100, and a group of on-vehicle sensors 200 are provided. In the CO ₂ recovery system, CO ₂ in the exhaust gas from the internal combustion engine 11 can be stored (in other words, recovered) in the CO ₂ storage device 40 . The configuration and functions of each part will be explained below.

The internal combustion engine 11 generates driving force for driving the vehicle 1 by internally burning fuel. In addition to the internal combustion engine 11, an electric motor (not shown) may be provided in the vehicle 1. In this case, the internal combustion engine 11 and the electric motor are used together to generate the driving force for driving the vehicle 1.

Exhaust gas (exhaust gas) generated by combustion of fuel within the internal combustion engine 11 flows into the exhaust pipe 13 through the exhaust manifold 12 . A purifier 14 is provided in the exhaust pipe 13. The exhaust pipe 13 includes an exhaust pipe 13a provided between the internal combustion engine 11 and the purifier 14, and an exhaust pipe 13b other than that. The exhaust pipe 13a is connected to the internal combustion engine 11 via the exhaust manifold 12. Exhaust gas discharged from the internal combustion engine 11 flows into the purification device 14 through the inside of the exhaust pipe 13a.

The purifier 14 purifies the exhaust gas that has flowed into it. Specifically, in the purification, the purifier 14 removes NO _x (nitrogen oxides), HC (hydrocarbons), CO (carbon monoxide), etc. in the exhaust gas that has flowed into the purifier 14 . The purification device 14 is configured with a catalyst suitable for removing _NOx , HC, CO, etc. (for example, a three-way catalyst, a _NOx storage reduction catalyst). However, the substance to be removed is not necessarily completely removed by the purifier 14, and some of the substance to be removed may pass through the purifier 14 depending on the concentration of the substance to be removed.

The exhaust gas purified by the purifier 14 flows into the flow path switching device 15 through the inside of the exhaust pipe 13b. A storage connection path 16 and an exhaust connection path 17 are connected to the flow path switching device 15 . The flow path switching device 15 sends out the exhaust gas flowing through the exhaust pipe 13b to either the storage connection path 16 or the exhaust connection path 17 under the control of the control device 100.

The control device 100 can switch between storage control and direct discharge control as described below. The storage control is a control for sending exhaust gas flowing into the flow path switching device 15 through the exhaust pipe 13b from the flow path switching device 15 to the storage connection path 16. Direct exhaust control is control in which exhaust gas flowing into the flow path switching device 15 through the exhaust pipe 13b is sent out from the flow path switching device 15 to the exhaust connection path 17.

FIG. 2 shows the flow of exhaust gas when storage control is performed. When storage control is performed, the exhaust gas sent from the flow path switching device 15 to the storage connection path 16 is supplied to the CO ₂ separation membrane 30 and separated into separated gas and residual gas by the CO ₂ separation membrane 30. .

The CO ₂ separation membrane 30 is a membrane that selectively passes only gaseous carbon dioxide out of the exhaust gas supplied to itself. In the storage control, the gas that has passed through the CO ₂ separation membrane 30 is sent as a separated gas to the CO ₂ storage device 40 through the separation gas path 18 . In storage control, the gas that has not passed through the CO ₂ separation membrane 30 is sent to the residual gas discharge path 19 as residual gas. The residual gas discharge path 19 is connected to a muffler 20, and the residual gas is discharged to the outside of the vehicle via the muffler 20. The outside of the vehicle refers to the outside of the vehicle 1.

FIG. 3 shows the flow of exhaust gas when direct exhaust control is performed. When direct exhaust control is performed, the exhaust gas sent from the flow path switching device 15 to the exhaust connection path 17 is exhausted to the outside of the vehicle via the muffler 20 without passing through the CO ₂ separation membrane 30.

The muffler 20 is an exhaust port for exhaust gas. Note that the residual gas is a part of the exhaust gas. The muffler 20 is connected to the exhaust connection path 17 and the residual gas discharge path 19. The muffler 20 has a function of reducing exhaust noise by lowering the temperature and pressure of the exhaust gas in the exhaust connection path 17 or the residual gas in the residual gas exhaust path 19.

The CO ₂ storage device 40 is connected to the separation gas path 18 and captures and stores CO ₂ in the separation gas that has passed through the CO ₂ separation membrane 30 . As a method for capturing and storing CO ₂ in the CO ₂ storage device 40, any method including known methods can be used. For example, as a method for capturing and storing _CO2 , a physical adsorption method, a physical absorption method, a chemical absorption method, or a cryogenic separation method can be used. As an example, the structure and function of the CO ₂ storage device 40 when a physical adsorption method is adopted will be explained. In this case, the CO ₂ storage device 40 includes a CO ₂ adsorbent such as activated carbon or zeolite, and a container containing the CO ₂ adsorbent. By bringing a CO ₂ -containing gas (the above-mentioned separated gas) into contact with the CO ₂ adsorbent, CO ₂ can be adsorbed onto the CO ₂ adsorbent.

Note that although the main component of the separated gas that has passed through the CO ₂ separation membrane 30 is CO ₂ , components other than CO ₂ may also be included in the separated gas as impurities. Of the separated gas sent to the CO ₂ storage device 40, the gas (including the above-mentioned impurities) that is not captured and stored in the CO ₂ storage device 40 is discharged to the outside of the vehicle via the muffler 20 or an outlet (not shown). Ru.

The structure of the flow path switching device 15 is shown in FIG. 4(a). The flow path switching device 15 may be a three-way solenoid valve. The flow path switching device 15 includes electromagnetic valves 15a and 15b. FIG. 4(a) conceptually shows the structure of the solenoid valves 15a and 15b, and the actual structure of the solenoid valves 15a and 15b may be different from that shown in FIG. 4(a) (see FIG. 4(b) below). ) and Figure 4(c) as well). Each of the electromagnetic valves 15a and 15b is controlled by the control device 100 to be in an open state or a closed state. The solenoid valve 15a is provided between the exhaust pipe 13b and the storage connection path 16, and exhaust gas from the exhaust pipe 13b flows into the storage connection path 16 only when the solenoid valve 15a is in an open state. The solenoid valve 15b is provided between the exhaust pipe 13b and the exhaust connection path 17, and exhaust gas flows into the exhaust connection path 17 from the exhaust pipe 13b only when the solenoid valve 15b is open. Therefore, in the storage control, the control device 100 controls the solenoid valve 15a to be in the open state, while the solenoid valve 15b is controlled to be in the closed state, as shown in FIG. 4(b). Conversely, in the direct discharge control, the control device 100 controls the solenoid valve 15a to be in the closed state, while the solenoid valve 15b is controlled to be in the open state, as shown in FIG. 4(c).

As shown in FIG. 5, the control device 100 includes an arithmetic processing section 110 and a memory 120. The arithmetic processing unit 110 includes an MPU (Micro Processing Unit), a GPU (Graphics Processing Unit), and the like. Any control, operation, and processing executed by the control device 100 may be understood as control, operation, and processing executed by the arithmetic processing unit 110. The MPU and the GPU may be integrally formed in the arithmetic processing unit 110 (for example, the MPU may have a built-in GPU).

The memory 120 includes nonvolatile memory such as ROM (Read Only Memory) or flash memory, and volatile memory such as RAM (Random Access Memory). Each function of the control device 100 may be realized by executing a program stored in the memory 120 in the arithmetic processing unit 110. The program here may include multiple programs. Each function of the control device 100 may be realized by providing a plurality of MPUs in the arithmetic processing unit 110 and executing a plurality of programs on the plurality of MPUs. The control device 100 may include one or more ECUs (Electronic Control Units). The arithmetic processing unit 110 may be configured by two or more MPUs in two or more ECUs.

The on-vehicle sensor group 200 consists of various sensors installed in the vehicle 1. FIG. 5 shows a rotation speed sensor 211, a vehicle speed sensor 212, a gear sensor 213, an accelerator sensor 214, a brake sensor 215, and a steering angle sensor 216 as sensors included in the vehicle-mounted sensor group 200. However, sensors not shown in FIG. 5 may also be included in the in-vehicle sensor group 200.

The number of rotations sensor 211 detects the number of revolutions of the engine (the number of revolutions of the crankshaft), which is the internal combustion engine 11, and generates and outputs number of revolutions information representing the detected number of revolutions. Vehicle speed sensor 212 detects the speed of vehicle 1 and outputs vehicle speed information (vehicle speed pulse) representing the detected speed. The gear sensor 213 detects the gear state or gear ratio of a transmission provided in the vehicle 1, and outputs gear information representing the detected gear state or gear ratio. The accelerator sensor 214 detects the amount of operation on an accelerator pedal provided in the vehicle 1 (the amount of operation by the driver), and outputs accelerator information representing the detected amount of operation. The brake sensor 215 detects the amount of operation on a brake pedal provided in the vehicle 1 (the amount of operation by the driver), and outputs brake information representing the detected amount of operation. The steering angle sensor 216 detects the steering angle (steering angle) of the vehicle 1 and outputs steering angle information representing the detected steering angle.

The driving state information includes the above-mentioned rotation speed information, vehicle speed information, gear information, accelerator information, brake information, and steering angle information. The driving state of the vehicle 1 is represented by the driving state information. It can be said that the sensors 211 to 216 are sensors for detecting the running state of the vehicle 1.

A communication network including a CAN (Controller Area Network) is formed in the vehicle 1. Each sensor in the control device 100 and the in-vehicle sensor group 200 is connected to the communication network, and can transmit and receive arbitrary information and signals via the communication network.

By using the CO ₂ storage device 40, CO ₂ in exhaust gas can be captured and stored (in other words, recovered). However, the concentration of CO ₂ in the exhaust gas is not so high, and it cannot be said that the capacity of the CO ₂ storage device 40 is fully utilized. For example, the concentration of CO ₂ in exhaust gas is about 10% for gasoline vehicles, and may be about 2 to 4% for diesel vehicles. Note that the vehicle 1 to which the present invention is applied may be a gasoline vehicle or a diesel vehicle. By increasing the concentration of CO ₂ in the gas supplied to the CO ₂ storage device 40, the capacity of the CO ₂ storage device 40 can be fully utilized. Considering this, in the CO ₂ recovery system according to the present embodiment, the CO ₂ separation membrane 30 is introduced to increase the concentration of CO ₂ in the gas supplied to the CO ₂ storage device 40.

On the other hand, when using a CO ₂ separation membrane, the gas is usually purified before being supplied to the CO ₂ separation membrane. During gas purification, substances harmful to the CO ₂ separation membrane are removed. Hazardous substances include _NOx and _SOx . _NOx refers to _nitrided oxides, such as NO, _NO2 , _{N2O4 , N2O3} or _N2O . _SOX refers to sulfur oxides, for example _SO2 or _SO3 .

The exhaust gas from the internal combustion engine 11 contains _NOx and _SOx . Although some of _{the NO X} and _SO The condensed water _generated when NO _{X or SO}

It is not realistic to provide a large amount of activated carbon or the like in the vehicle 1 in order to render all _NOx and _SOx in the exhaust gas harmless. This is because the space that can be secured in the vehicle 1 is limited. On the other hand, in regulations related to exhaust gas, _{the average} amount of NO _X or _SO There will be no problem even if it is done.

Taking all of these into consideration, the CO ₂ recovery system according to the present embodiment directly discharges exhaust gas to the outside of the vehicle without passing through the CO ₂ separation membrane 30 in a situation where a high concentration of NO _X or SO _X is discharged. When the _{concentration of} NO _{X or SO}

Hereinafter, some specific operation examples, application techniques, modification techniques, etc. related to the CO ₂ recovery system will be described in a plurality of embodiments. The matters described above in this embodiment apply to each of the following examples unless otherwise specified and unless there is a contradiction. In each embodiment, if there is a matter inconsistent with the above-mentioned matter, the description in each embodiment may take precedence. Further, unless there is a contradiction, matters described in any one of the plurality of embodiments shown below can be applied to any other embodiment (i.e., any two or more of the plurality of embodiments). It is also possible to combine the embodiments).

Note that in the following description, the target substance refers to _NOx or _SOx . NO _X as a target substance includes all or a part of NO, NO ₂ , N ₂ O ₄ , N ₂ O ₃ and N ₂ O. _SOX as a target substance includes all or part of _SO2 and _SO3 . In the following description, concentration may be any defined concentration, for example, mass percent concentration or volume percent concentration. The concentration of the target substance is referred to by the symbol "C _NS ". The concentration of the target substance _CNS refers to the concentration of the target substance in the exhaust gas in the exhaust pipe 13b. However, the concentration of the target substance in the exhaust gas in the exhaust pipe 13a may be the concentration _CNS of the target substance.

<<First Example>>
A first example will be explained.

The arithmetic processing unit 110 selectively executes storage control or direct discharge control depending on the concentration _CNS of the target substance. By the storage control, the exhaust gas from the internal combustion engine 11 is guided to the flow path toward the CO ₂ separation membrane 30 (that is, the exhaust gas in the exhaust pipe 13b is guided to the flow path including the storage connection path 16). As a result, CO ₂ in the exhaust gas is captured and stored (in other words, recovered) in the CO ₂ storage device 40 through the CO ₂ separation membrane 30. Direct exhaust control allows exhaust gas from the internal combustion engine 11 to be guided to the flow path toward the muffler 20 without passing through the CO ₂ separation membrane 30 (exhaust gas in the exhaust pipe 13b is guided to the flow path including the exhaust connection path 17). ). As a result, exhaust gas from the internal combustion engine 11 is discharged to the outside of the vehicle through the flow path.

By switching and executing storage control or direct discharge control according to the concentration _CNS of the target substance, it is possible to both comply with exhaust gas regulations and extend the life of the CO ₂ separation membrane 30.

More specifically, the calculation processing unit 110 compares the concentration C _NS of the target substance with a predetermined reference concentration C _REF . Then, when it is determined that the concentration C _NS of the target substance is lower than the reference concentration C _REF , the arithmetic processing unit 110 executes storage control. When it is determined that the concentration C _NS of the target substance exceeds the reference concentration C _REF , the arithmetic processing unit 110 directly executes discharge control.

This makes it possible to both comply with exhaust gas regulations and extend the life of the CO ₂ separation membrane 30. Note that when it is determined that the concentration C _NS of the target substance matches the reference concentration C _REF , the arithmetic processing unit 110 may perform either storage control or direct discharge control.

When the target substance is NO _X , the fact that the concentration C _NS of the target substance is lower than the reference concentration C _REF means that the concentration of NO _X is lower than the reference concentration C _REF . The same applies when the target substance is _SOx . When _{considering that both NO X and SO} It's good to understand that. In this case, when at least one of the concentrations of NO _X and SO _X exceeds the reference concentration C _REF , it is understood that the concentration C _NS of the target substance exceeds the reference concentration C _REF .

<<Second Example>>
A second embodiment will be explained. The second embodiment is implemented in combination with the first embodiment.

In the second embodiment, the arithmetic processing unit 110 executes an air-fuel ratio estimation process for estimating the air-fuel ratio of the internal combustion engine 11. Then, the arithmetic processing unit 110 may determine the level relationship between the concentration C _NS of the target substance and the reference concentration C _REF based on the estimation result of the air-fuel ratio.

As a result, the height relationship between the concentration C _NS and C _REF can be estimated without the need to directly detect the concentration C _NS of the target substance, thereby ensuring compliance with exhaust gas regulations and extending the life of the CO ₂ separation membrane 30. It is possible to achieve both.

The air-fuel ratio estimated by the air-fuel ratio estimation process is hereinafter referred to as an estimated air-fuel ratio. The arithmetic processing unit 110 can determine the level relationship between the target substance concentration C _NS and the reference concentration C _REF based on the difference between the estimated air-fuel ratio and the stoichiometric air-fuel ratio. The stoichiometric air-fuel ratio is the air-fuel ratio at which the oxygen in the air-fuel mixture input to the fuel engine 11 and the fuel react in just the right amount, and the stoichiometric air-fuel ratio is known to the arithmetic processing unit 110. The larger the difference between the actual air-fuel ratio and the stoichiometric air-fuel ratio, the more the target substance is likely to be contained in the exhaust gas from the internal combustion engine 11.

Therefore, the calculation processing unit 110 compares the magnitude of the difference DIF _AF1 between the estimated air-fuel ratio and the stoichiometric air-fuel ratio with a predetermined deviation threshold TH _AF . When the magnitude of the difference DIF _AF1 between the estimated air-fuel ratio and the stoichiometric air-fuel ratio is larger than the deviation threshold TH _AF , the calculation processing unit 110 determines that the concentration C _NS of the target substance exceeds the reference concentration C _REF . When the magnitude of the difference DIF _AF1 between the estimated air-fuel ratio and the stoichiometric air-fuel ratio is less than or equal to the deviation threshold TH _AF , the calculation processing unit 110 determines that the concentration C _NS of the target substance is lower than the reference concentration C _REF . The arithmetic processing unit 110 does not necessarily need to specifically estimate the value of the concentration _CNS of the target substance. It is sufficient for the arithmetic processing unit 110 to determine whether the concentration C _NS of the target substance exceeds the reference concentration C _REF based on the size DIF _AF1 .

Note that the deviation threshold TH _AF when the estimated air-fuel ratio is larger than the stoichiometric air-fuel ratio may be different from the deviation threshold TH _AF when the estimated air-fuel ratio is smaller than the stoichiometric air-fuel ratio.

The arithmetic processing unit 110 can estimate the air-fuel ratio of the internal combustion engine 11 based on the running state of the vehicle 1, and can therefore determine whether the concentration _CNS of the target substance exceeds the reference concentration _CREF based on the running state of the vehicle 1. . The arithmetic processing unit 110 can recognize the running state of the vehicle 1 based on the running state information (see FIG. 5).

Since the air-fuel ratio depends on the running state of the vehicle 1, the air-fuel ratio can be estimated satisfactorily based on the running state of the vehicle 1.

For example, when the internal combustion engine 11 is started, the actual air-fuel ratio deviates greatly from the stoichiometric air-fuel ratio. Therefore, when the vehicle 1 starts, the arithmetic processing unit 110 can determine that the magnitude DIF _AF1 is larger than the deviation threshold TH _AF . More specifically, for example, during a start response period during a start process in which the vehicle moves from a stopped state to a started state to a running state, the arithmetic processing unit 110 determines that the magnitude DIF _AF1 is larger than the deviation threshold TH _AF . It's good. Here, the vehicle stopped state refers to a state in which the internal combustion engine 11 is not operating and the vehicle 1 is stopped. The starting state refers to a state in which the internal combustion engine 11 is operating but the vehicle 1 is still stopped. The vehicle running state refers to a state in which the vehicle 1 is running based on the driving force generated by the internal combustion engine 11. The start response period refers to the period from when the internal combustion engine 11 starts operating until the speed of the vehicle 1 reaches a predetermined speed (for example, 5 km/h) in the above-mentioned start process. The arithmetic processing unit 110 can determine whether the current moment belongs to the start support period based on the driving state information (see FIG. 5). The magnitude DIF _AF1 may be determined to be larger than the deviation threshold TH _AF for a certain period of time after the vehicle changes from the stopped state to the started state.

For example, during coasting, the actual air-fuel ratio deviates significantly from the stoichiometric air-fuel ratio. When the vehicle 1 is coasting, the arithmetic processing unit 110 may determine that the magnitude DIF _AF1 is larger than the deviation threshold TH _AF . Coasting refers to the vehicle 1 coasting without accelerating the vehicle 1 by depressing the accelerator pedal or decelerating the vehicle 1 by depressing the brake pedal. The arithmetic processing unit 110 can determine whether coasting is currently being performed based on the driving state information (see FIG. 5).

<<Third Example>>
A third embodiment will be explained. The third embodiment is implemented in combination with the first embodiment.

The vehicle 1 may be provided with an air-fuel ratio sensor (not shown) that measures the air-fuel ratio of the internal combustion engine 11. In this case, instead of executing the air-fuel ratio estimation process, the arithmetic processing unit 110 determines the height relationship between the target substance concentration C _NS and the reference concentration C _REF based on the measurement results of the air-fuel ratio by the air-fuel ratio sensor. good.

As a result, the height relationship between the concentration C _NS and C _REF can be estimated without the need to directly detect the concentration C _NS of the target substance, thereby ensuring compliance with exhaust gas regulations and extending the life of the CO ₂ separation membrane 30. It is possible to achieve both.

The air-fuel ratio measured by the air-fuel ratio sensor is hereinafter referred to as the measured air-fuel ratio. The air-fuel ratio sensor is installed in the exhaust pipe 13a or 13b, and outputs a signal representing the measured air-fuel ratio by measuring the oxygen concentration in the exhaust gas in the exhaust pipe 13a or 13b. The output signal of the air-fuel ratio sensor is transmitted to the arithmetic processing unit 110 via a communication network including CAN, so that the arithmetic processing unit 110 acquires and recognizes the measured air-fuel ratio.

The arithmetic processing unit 110 can determine the level relationship between the target substance concentration C _NS and the reference concentration C _REF based on the difference between the measured air-fuel ratio and the stoichiometric air-fuel ratio.

Specifically, the arithmetic processing unit 110 compares the magnitude of the difference DIF _AF2 between the measured air-fuel ratio and the stoichiometric air-fuel ratio with a predetermined deviation threshold TH _AF . When the magnitude of the difference DIF _AF2 between the measured air-fuel ratio and the stoichiometric air-fuel ratio is larger than the deviation threshold TH _AF , the arithmetic processing unit 110 determines that the concentration C _NS of the target substance exceeds the reference concentration C _REF . When the magnitude of the difference DIF _AF2 between the measured air-fuel ratio and the stoichiometric air-fuel ratio is less than or equal to the deviation threshold TH _AF , the calculation processing unit 110 determines that the concentration C _NS of the target substance is lower than the reference concentration C _REF . The arithmetic processing unit 110 does not necessarily need to specifically estimate the value of the concentration _CNS of the target substance. It is sufficient for the calculation processing unit 110 to determine whether the concentration C _NS of the target substance exceeds the reference concentration C _REF based on the size DIF _AF2 .

Note that the deviation threshold TH _AF when the measured air-fuel ratio is larger than the stoichiometric air-fuel ratio may be different from the deviation threshold TH _AF when the measured air-fuel ratio is smaller than the stoichiometric air-fuel ratio.

<<Fourth Example>>
A fourth embodiment will be explained. The fourth embodiment is implemented in combination with the first embodiment.

The concentration _CNS of the target substance depends on the driving state of the vehicle 1. Therefore, the arithmetic processing unit 110 estimates the concentration _CNS of the target substance based on the driving state information (see FIG. 5) representing the driving state of the vehicle 1, so that the concentration _CNS of the target substance exceeds the reference concentration _CREF. You can decide whether or not to exceed it.

As a result, the height relationship between the concentration C _NS and C _REF can be estimated without the need to directly detect the concentration C _NS of the target substance, thereby ensuring compliance with exhaust gas regulations and extending the life of the CO ₂ separation membrane 30. It is possible to achieve both.

For example, table data representing the relationship between the rotation speed of the internal combustion engine 11, the gear ratio of the transmission provided in the vehicle 1, and the concentration _CNS is created in advance and stored in the memory 120. In this case, the arithmetic processing unit 110 can estimate the concentration C _NS based on the table data, rotation speed information, and gear information, and determine whether the concentration C _NS exceeds the reference concentration C _REF based on the estimation result. The same applies when information other than rotational speed information and gear information is used in the driving state information.

Further, after a learned model is created in a machine learning process through a learning data creation process, the learned model may be incorporated into the arithmetic processing unit 110. The learned model here refers to an algorithm for determining whether the concentration C _NS of the target substance exceeds the reference concentration C _REF based on the driving state information (see FIG. 5). The method will be explained with reference to the flowchart in FIG.

First, in step S1, a learning data creation process is performed. In the learning data creation process, by actually measuring the actual concentration _CNS of the target substance in the exhaust pipe 13b in a certain driving condition, the data is calculated from the pair of driving condition information representing the driving condition at that time and the actually measured concentration _CNS . Create a set of data consisting of: In the learning data creation step, first to Nth sets of data are created by creating sets of data under various driving conditions. The driving state information differs between any two or more sets of data among the first to Nth sets of data (however, they may match by chance). N is an integer of 2 or more, for example 10,000 to 100,000. A learning data set is formed by the first to Nth set of data.

After the learning data set is obtained, the process proceeds to the machine learning process of step S2. A machine learning device is used in the machine learning process. The machine learning device is any computer device, and may be the control device 100 itself. In the machine learning process, the machine learning device causes a neural network (hereinafter referred to as NN) provided within the machine learning device to perform machine learning using the learning data set. The machine learning here is supervised machine learning using the concentration _CNS in each set of data as teacher data. The NN receives driving state information as input data, and derives an estimated concentration value as output data based on the input data. The estimated concentration value derived by the NN is the estimated value of the concentration _CNS of the target substance by the NN. After undergoing machine learning in the machine learning process, the NN becomes a trained model that can satisfactorily estimate the concentration C _NS based on the driving state information.

With the obtained learned model installed in the arithmetic processing unit 110, the process proceeds to step S3, the actual operation process. In the actual operation process, the arithmetic processing unit 110 uses the trained model to determine whether the concentration _CNS of the target substance exceeds the reference concentration _CREF based on the driving state information (see FIG. 5) representing the driving state of the vehicle 1. to judge.

<<Fifth Example>>
A fifth embodiment will be explained. The fifth embodiment is implemented in combination with the first embodiment.

A concentration sensor (not shown) may be installed in the vehicle 1 to measure the concentration _CNS of the target substance. The concentration sensor is inserted into the exhaust pipe 13b and measures the concentration _CNS of the target substance in the exhaust gas in the exhaust pipe 13b. As a modification, the concentration sensor may be inserted into the exhaust pipe 13a and measure the concentration _CNS of the target substance in the exhaust gas in the exhaust pipe 13a.

The concentration C _NS of the target substance measured by the concentration sensor is particularly referred to as the measured concentration C _NS . The concentration sensor outputs a signal representing the measured concentration _CNS . The output signal of the concentration sensor is transmitted to the arithmetic processing section 110 via a communication network including CAN, so that the arithmetic processing section 110 acquires and recognizes the measured concentration _CNS .

The arithmetic processing unit 110 according to the fifth embodiment uses a concentration sensor to determine the height relationship between the concentration C _NS (measured concentration C _NS ) and the reference concentration C _REF , and performs storage control or direct discharge control based on the determination result. Execute. That is, when it is determined that the measured concentration C _NS of the target substance is lower than the reference concentration C _REF , the arithmetic processing unit 110 executes storage control. If it is determined that the measured concentration C _NS of the target substance exceeds the reference concentration C _REF , the arithmetic processing unit 110 directly executes discharge control.

This makes it possible to both comply with exhaust gas regulations and extend the life of the CO ₂ separation membrane 30. Note that when it is determined that the measured concentration C _NS of the target substance matches the reference concentration C _REF , the arithmetic processing unit 110 may perform either storage control or direct discharge control.

Note that in the method according to the fifth embodiment, after the concentration C _NS of the target substance actually increases beyond the reference concentration C _REF and this increase is recognized by the arithmetic processing unit 110, the discharge control is performed directly from the storage control. (and vice versa). Therefore, the method of the fifth embodiment may be inferior in real-time performance compared to the methods of the second to fourth embodiments. Taking this point into consideration, the methods of the second to fourth embodiments may be preferable to the method of the fifth embodiment.

<<Sixth Example>>
A sixth embodiment will be explained. In the sixth embodiment, an example of an operation procedure related to switching between storage control and direct discharge control will be described. FIG. 7 is an operation flowchart related to switching between storage control and direct discharge control.

The start of supply of drive power to the control device 100 leads to step S11. In step S11, the arithmetic processing unit 110 executes storage control as initial control. The arithmetic processing unit 110 can transmit a first command signal or a second command signal to the flow path switching device 15 from the interface of the control device 100 . The first command signal is control for realizing storage control. Upon receiving the first command signal, the flow path switching device 15 opens the electronic valve 15a and closes the electronic valve 15b (see FIG. 4(b)). The second command signal is a control for realizing direct emission control. Upon receiving the second command signal, the flow path switching device 15 closes the electronic valve 15a and opens the electronic valve 15b (see FIG. 4(c)). Therefore, in step S11, the arithmetic processing unit 110 transmits a first command signal to the flow path switching device 15 from the interface of the control device 100, thereby executing storage control.

In step S12 following step S11, the arithmetic processing unit 110 specifies the concentration _CNS of the target substance using the method shown in any of the second to fifth embodiments. Concentration _CNS is determined by estimation or measurement. After that, the process advances to step S13.

In step S13, the arithmetic processing unit 110 determines whether the specified concentration C _NS exceeds a predetermined reference concentration C _REF . In the judgment here, any of the methods shown in the second to fifth embodiments may be adopted. If it is determined that the concentration C _NS exceeds the reference concentration C _REF (Y in step S13), the process advances to step S14. If it is determined that the concentration C _NS does not exceed the reference concentration C _REF (N in step S13), the process returns to step S12.

In step S14, the arithmetic processing unit 110 transmits a second command signal to the flow path switching device 15 from the interface of the control device 100. As a result, the control executed by the arithmetic processing unit 110 switches from storage control to direct discharge control. After this, the direct discharge control is continuously executed until reaching step S16, which will be described later.

After step S14, the process advances to step S15. In step S15, the arithmetic processing unit 110 determines whether a predetermined return condition is met. If it is determined that the return condition is satisfied (Y in step S15), the process proceeds to step S16, and if not (N in step S15), the determination operation in step S15 is repeated.

In step S16, the arithmetic processing unit 110 transmits a first command signal to the flow path switching device 15 from the interface of the control device 100. As a result, the control executed by the arithmetic processing unit 110 switches from direct discharge control to storage control. After this, the process returns to step S12.

The return conditions will be explained. For example, the return condition may be satisfied when a predetermined period of time has elapsed after the control executed by the arithmetic processing unit 110 was switched from storage control to direct discharge control. The predetermined time here is a predetermined time, for example, about several seconds. Alternatively, for example, in step S15, when the calculation processing unit 110 determines that the estimated or measured concentration C _NS is lower than the reference concentration C _REF , the return condition may be satisfied.

The operating procedure shown in FIG. 7 makes it possible to comply with exhaust gas regulations while suppressing deterioration of the CO ₂ separation membrane 30 due to high concentration target substances.

<<Seventh Example>>
A seventh embodiment will be explained. The arithmetic processing unit 110 determines whether the concentration C _NS of the target substance exceeds the reference concentration C _REF at each time. Therefore, the arithmetic processing unit 110 can measure the duration when the concentration C _NS of the target substance continues to exceed the reference concentration C _REF . Hereinafter, this duration will be referred to as high concentration duration. The high concentration duration time is the time during which the concentration C _NS of the target substance exceeds the reference concentration C _REF without interruption.

The arithmetic processing unit 110 may be able to execute a notification process to notify the notification recipient according to the high concentration duration time. For example, when the high concentration duration exceeds a predetermined determination time, the calculation processing unit 110 performs notification processing. The notification recipient is basically the driver of the vehicle 1. However, the notification recipient may be a passenger other than the driver of the vehicle 1, a manager, or the like.

The notification in the notification process may be realized by displaying on a display device. Specifically, for example, in the notification process, the arithmetic processing unit 110 performs display control to display a notification image including a predetermined message on a display device (not shown) installed near the driver's seat of the vehicle 1. The message in the notification image includes, for example, words such as "Let's try eco-driving to protect the environment." This is expected to make it easier to practice eco-driving that reduces emissions of target substances, and is expected to extend the life of the CO ₂ separation membrane 30 by reducing emissions of target substances. The display device on which the notification image is displayed may be a display device of a mobile terminal owned by the notification recipient (for example, a smartphone owned by the driver of the vehicle 1).

The arithmetic processing unit 110 may change the content of the notification in the notification process as the high concentration duration increases. That is, for example, the arithmetic processing unit 110 performs the first notification process when the high concentration duration exceeds a predetermined first determination time but is less than or equal to a predetermined second determination time; 2nd notification processing may be performed when the number exceeds . Here, the second determination time is longer than the first determination time. The message in the notification image may be different between the first and second notification processes. The message in the second notification process may be a message that more strongly recommends eco-driving than the message in the first notification process.

The notification in the notification process may include notification by audio output in addition to or in place of the display on the display device.

<<Eighth Example>>
An eighth embodiment will be explained. FIG. 8 shows a functional block diagram of the control device 100. It can be considered that the control device 100 is provided with functional blocks F1 to F3. The functional blocks F1 to F3 may be realized by executing a single program or a plurality of programs in the arithmetic processing unit 110. A plurality of MPUs may be provided in the arithmetic processing unit 110, and a plurality of arbitrary functional blocks may be realized by individually executing a plurality of programs on the plurality of MPUs.

Functional blocks F1, F2, and F3 are a concentration determining section, a control switching section, and a notification processing section, respectively. The concentration determination unit F1 determines the level relationship between the concentration C _NS of the target substance and the reference concentration C _REF using the method shown in any of the embodiments described above. The control switching unit F2 switches the control to be executed between the storage control and the direct discharge control based on the determination result of the concentration determination unit F1 (in other words, switches and executes the storage control or the direct discharge control). The notification processing unit F3 performs the notification processing shown in the seventh embodiment.

When focusing on switching the exhaust gas flow path by switching between storage control and direct discharge control, it can be said that the control device 100 functions as a flow path control device. Control device 100 may also include various other functions (for example, a function to control travel of vehicle 1).

<<Ninth Example>>
A ninth embodiment will be explained. In the ninth embodiment, modification techniques or supplementary matters for each of the above-mentioned matters will be explained.

The CO ₂ stored in the CO ₂ storage device 40 is released into the CO ₂ storage device when the CO ₂ storage device 40 is connected to a recovery device (not shown) installed at a gas station or garage, for example. 40 to a collection device. Alternatively, the CO 2 stored in the CO ₂ storage device 40 may be taken out of the vehicle by removing the entire CO ₂ storage device 40 or the cartridge in _the CO ₂ storage device 40 from the vehicle 1. In this case, after the CO ₂ storage device 40 or cartridge installed in the vehicle 1 is replaced with a new one, the CO ₂ recovery system is started again.

The concentration _CNS of the target substance depends on the combustion temperature of the fuel in the internal combustion engine 11. For this reason, the arithmetic processing unit 110 may determine the level relationship between the target substance concentration C _NS and the reference concentration C _REF according to the combustion temperature of the fuel in the internal combustion engine 11 . Since it is difficult to directly measure the combustion temperature, the arithmetic processing unit 110 may estimate the combustion temperature based on driving state information (see FIG. 5).

As a device related to exhaust gas, a device (hereinafter referred to as an additional device) not shown in each of the above-mentioned drawings may be provided in the vehicle 1. An exhaust gas cooling device may be installed in the vehicle 1 as an additional device. The exhaust gas cooling device is disposed upstream of the CO ₂ separation membrane 30 in the exhaust gas flow path, and reduces the temperature of the exhaust gas flowing into the CO ₂ separation membrane 30. By installing the exhaust gas cooling device, deterioration of the CO ₂ separation membrane 30 due to heat can be suppressed. An energy conversion device may be installed in the vehicle 1 as an additional device. The energy conversion device converts thermal energy contained in exhaust gas into other energy (such as electrical energy). Other energy obtained by the conversion (electrical energy, etc.) can be used in the vehicle 1. Passing the exhaust gas through the energy conversion device lowers the temperature of the exhaust gas. Therefore, the energy conversion device can be said to be a type of exhaust gas cooling device. An energy conversion device may be disposed upstream of the CO ₂ separation membrane 30 in the exhaust gas flow path, and the temperature of the exhaust gas flowing into the CO ₂ separation membrane 30 may be lowered by the energy conversion device.

In the structure shown in FIG. 1, when storage control (see FIG. 2) is performed, part of the exhaust gas is sent to the muffler 20 after passing through the CO ₂ separation membrane 30. However, when storage control is performed, the exhaust gas that has passed through the flow path switching device 15 is first supplied to a pre-separation muffler (not shown), and the exhaust gas that has passed through the pre-separation muffler is supplied to the CO ₂ separation membrane 30. Altered configurations may also be employed. The pre-separation muffler may be the muffler 20, or may be a muffler installed separately from the muffler 20 in the vehicle 1. In this modified configuration, since the temperature of the exhaust gas flowing into the CO ₂ separation membrane 30 can be lowered by the pre-separation muffler, deterioration of the CO ₂ separation membrane 30 due to heat can be suppressed. The pre-separation muffler may be understood as a type of exhaust gas cooling device described above. Even in the modified configuration, the gas that has passed through the CO ₂ separation membrane 30 is sent as a separated gas to the CO ₂ storage device 40 through the separated gas path 18 . The gas that has not passed through the CO ₂ separation membrane 30 is discharged as residual gas to the outside of the vehicle from an exhaust port (which may be the muffler 20) installed in the vehicle 1.

The CO ₂ recovery system according to this embodiment is configured to include at least a control device 100, a CO ₂ separation membrane 30, a CO ₂ storage device 40, and a flow path switching device 15. However, any of the components described above as being mounted on the vehicle 1 may be included in the components of the CO ₂ recovery system.

It is also possible to apply the CO ₂ recovery system or the present invention embodied in the CO ₂ recovery system to any use other than vehicle-mounted use.

The vehicle 1 is an example of a moving body that moves using a driving force generated using an internal combustion engine 11. In the present invention, the moving object may be one that is not classified as a vehicle (for example, a robot or a drone).

A program that causes a computer to execute any method described in the embodiment of the present invention, and a computer-readable nonvolatile recording medium that records the program are within the scope of the embodiment of the present invention. include. Any processing in the embodiments of the present invention may be realized by hardware such as a semiconductor integrated circuit, software equivalent to the above program, or a combination of hardware and software. There may be a plurality of software and hardware here.

The embodiments of the present invention can be appropriately modified in various ways within the scope of the technical idea shown in the claims. The above embodiments are merely examples of the embodiments of the present invention, and the meanings of the terms of the present invention and each component are not limited to those described in the above embodiments. The specific numerical values shown in the above-mentioned explanatory text are merely examples, and it goes without saying that they can be changed to various numerical values.

1 Vehicle 11 Internal combustion engine 12 Exhaust manifold 13, 13a, 13b Exhaust pipe 14 Purification device 15 Flow path switching device 15a, 15b Solenoid valve 16 Storage connection path 17 Exhaust connection path 18 Separation gas path 19 Residual gas discharge path 20 Muffler 30 CO ₂ separation membrane 40 CO ₂ storage device 100 Control device 110 Arithmetic processing unit 120 Memory 200 On-vehicle sensor group 211 Rotational speed sensor 212 Vehicle speed sensor 213 Gear sensor 214 Accelerator sensor 215 Brake sensor 216 Rudder angle sensor F1 Concentration determination unit F2 Control switching unit F3 Notification processing unit

Claims (11)

comprising a processing unit that controls exhaust gas from an internal combustion engine mounted on the vehicle to be guided to the first flow path or the second flow path,
CO ₂ in the exhaust gas guided to the first flow path is supplied to a CO ₂ storage device in the vehicle through a CO ₂ separation membrane,
The processing unit is a flow path control device for CO ₂ storage in a vehicle, wherein the processing section controls guiding the exhaust gas to the first flow path or the second flow path depending on the concentration of a target substance contained in the exhaust gas. When it is determined that the concentration of the target substance is lower than a predetermined reference concentration, the processing unit performs first control to guide the exhaust gas to the first flow path, so that the concentration of the target substance exceeds the reference concentration. The flow path control device for storing CO 2 in a vehicle according to claim 1, which performs second control to guide the exhaust gas to the second flow path when it is determined that the flow path control device for CO ₂ storage in a vehicle. 3. The CO ₂ storage device in a vehicle according to claim 2, wherein the processing unit determines a height relationship between the concentration of the target substance and the reference concentration based on an estimation result or a measurement result of the air-fuel ratio of the internal combustion engine. flow path control device. 4. The flow path control device for CO ₂ storage in a vehicle according to claim 3, wherein the processing unit estimates an air-fuel ratio of the internal combustion engine based on a running state of a vehicle having the internal combustion engine. The processing unit according to claim 2, wherein the processing unit determines the level relationship between the concentration of the target substance and the reference concentration based on output information of a sensor for detecting a running state of a vehicle having the internal combustion engine. A flow path control device for storing _CO2 in a vehicle. 3. The method for storing _CO2 in a vehicle according to claim 2, wherein the processing unit determines a height relationship between the concentration of the target substance and the reference concentration using a concentration sensor that measures the concentration of the target substance. Flow path control device. When the processing unit determines that the concentration of the target substance exceeds a predetermined reference concentration while the first control is being executed, the processing unit switches the control to be executed to the second control, and then the return condition is satisfied. The flow path control device for CO ₂ storage in a vehicle according to claim 1 , wherein the flow path control device then returns to the first control. When the exhaust gas is guided to the first flow path, CO ₂ in the exhaust gas is stored in the CO ₂ storage device through the CO ₂ separation membrane, and when the exhaust gas is led to the second flow path, the exhaust gas is The flow path control device for storing CO 2 in a vehicle according to any one of claims 1 to 7, wherein CO ₂ is discharged outside the vehicle having the internal combustion engine through the second flow path. The flow path control device for storing CO ₂ in a vehicle according to any one of claims 1 to 7, wherein the target substance is a nitrogen oxide or a sulfur oxide. A flow path control device according to any one of claims 1 to 7,
The CO ₂ separation membrane;
The CO ₂ storage device;
a flow path switching device connected to the first flow path and the second flow path and guiding the exhaust gas from the internal combustion engine to the first flow path or the second flow path according to control of the processing section; Equipped with a CO ₂ recovery system in vehicles. A flow path control step for guiding exhaust gas from the internal combustion engine to a first flow path or a second flow path,
CO ₂ in the exhaust gas guided to the first flow path is supplied to a CO ₂ storage device through a CO ₂ separation membrane,
In the flow path control step, the exhaust gas is guided to the first flow path or the second flow path depending on the concentration of a target substance contained in the exhaust gas. A flow path control method for CO ₂ storage in a vehicle.