Engine System

Abstract

To reduce emission of NOx by making CO2 in an exhaust gas usable as an EGR gas with a simple device configuration utilizing existing devices.SOLUTION: In an engine system, an amine-based solution cooled by a heat exchanger is supplied to a mixer, a CO2 gas included in an exhaust gas is absorbed by the amine-based solution by mixing the amine-based solution and the exhaust gas flowing in an exhaust pipe in the mixer, the amine-based solution absorbing the CO2 gas is supplied to an engine, the amine-based solution heated by the engine is supplied to a gas-liquid separator from the engine, the CO2 gas released from the amine-based solution by the heating, is separated from the amine-based solution heated by the engine, and the CO2 gas separated from the amine-based solution by the gas-liquid separator is supplied to an intake pipe from the gas-liquid separator through a recirculation pipe to be mixed in intake air.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an engine system. [Background technology]

[0002] Conventionally, exhaust gases emitted from vehicles contain greenhouse gases such as carbon dioxide (hereinafter referred to as CO2). It is said that global warming is caused by the emission of such greenhouse gases. In order to curb global warming, development of technologies to reduce the amount of CO2 emitted from vehicles is underway.

[0003] Patent Document 1 discloses a technology for reducing the amount of CO2 in exhaust gas discharged into the atmosphere by capturing CO2 in the exhaust gas emitted from an engine and storing the captured CO2 in a storage device.

[0004] In addition to CO2, exhaust gases emitted from engines also contain nitrogen oxides (hereinafter referred to as NOx). When NOx is emitted from vehicles, it undergoes photochemical reactions in the atmosphere and can cause photochemical smog, acid rain, and global warming. For this reason, there is a demand to reduce the amount of NOx emitted from vehicles.

[0005] In this regard, Patent Document 1 also discloses exhaust gas recirculation (EGR) that reduces the emission of NOx compounds by returning CO2 recovered from exhaust gas to the intake air of the engine. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Special Publication No. 2014-509360 Summary of the Invention [Problem to be solved by the invention]

[0007] However, as described in Patent Document 1, in order to use the CO2 gas captured from the exhaust gas as the EGR gas, various devices must be installed separately in addition to a refrigerant system for cooling the engine. Specifically, a device for capturing CO2 from the exhaust gas and a flow path system for recirculating the captured CO2 gas to the intake air of the engine must be installed separately. This causes a problem that the device configuration of the engine system becomes complicated and the manufacturing cost increases.

[0008] Therefore, the present invention aims to provide an engine system that can reduce NOx emissions by making it possible to use CO2 in exhaust gas as EGR gas with a simple device configuration that utilizes existing equipment. [Means for solving the problem]

[0009] In order to solve the above problem, an engine system according to an embodiment of the present invention comprises: The engine, an intake pipe connected to the engine; an exhaust pipe connected to the engine; a coolant flow path through which a coolant for cooling the engine circulates; a mixer provided at an intersection between the exhaust pipe and the refrigerant flow path; a heat exchanger provided upstream of the mixer in the refrigerant flow path; a gas-liquid separator provided in the refrigerant flow path between the heat exchanger and the engine; a return pipe connecting the gas-liquid separator and the intake pipe; Equipped with The refrigerant flow path is a first refrigerant flow path connecting the heat exchanger and the mixer; a second refrigerant flow path connecting the mixer and the engine; a third refrigerant flow path connecting the engine and the gas-liquid separator; a fourth refrigerant flow path connecting the gas-liquid separator and the heat exchanger; Including, The refrigerant is an amine-based solution, The amine-based solution cooled by the heat exchanger is supplied from the heat exchanger through the first refrigerant flow path to the mixer; In the mixer, the amine-based solution cooled by the heat exchanger is mixed with the exhaust gas flowing through the exhaust pipe, thereby causing CO2 gas contained in the exhaust gas to be absorbed into the amine-based solution; The amine-based solution having absorbed the CO2 gas is supplied from the mixer through the second refrigerant passage to the engine, The amine-based solution heated by the engine is supplied from the engine through the third refrigerant flow path to the gas-liquid separator; In the gas-liquid separator, CO2 gas released from the amine-based solution due to heating is separated from the amine-based solution heated by the engine; The amine-based solution from which the CO2 gas has been separated by the gas-liquid separator is supplied from the gas-liquid separator to the heat exchanger through the fourth refrigerant flow path; The CO2 gas separated from the amine-based solution by the gas-liquid separator is supplied from the gas-liquid separator through the return pipe to the intake pipe and mixed with the intake air. Effect of the Invention

[0010] According to the present invention, with a simple device configuration using existing equipment, it is possible to reduce NOx emissions by making it possible to use CO2 in exhaust gas as EGR gas. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic configuration diagram of an engine system according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic configuration diagram of an engine system according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The specific dimensions, materials, numerical values, etc. shown in the embodiment are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In this specification and drawings, elements having substantially the same functions and configurations are given the same reference numerals to avoid repeated explanations, and elements not directly related to the present invention are not shown.

[0013] [1. Overall configuration of engine system] First, the overall configuration of an engine system 100 according to a first embodiment of the present invention will be described with reference to Fig. 1. Fig. 1 is a schematic configuration diagram of the engine system 100 according to the first embodiment of the present invention.

[0014] 1, a vehicle 10 of this embodiment includes an engine system 100. The engine system 100 includes an engine 200, an intake pipe 300, an exhaust pipe 400, a refrigerant flow path 500, a mixer 600, a heat exchanger 700, a gas-liquid separator 800, and a return pipe 900.

[0015] The engine 200 is an internal combustion engine that outputs kinetic energy by repeating the process of compressing a mixture of fuel and air, igniting, burning, and expanding the mixture. The engine 200 according to this embodiment is a vehicle engine, particularly a gasoline engine. However, the engine 200 is not limited to this, and may be a diesel engine, a marine engine, a gas turbine engine, or other internal combustion engine.

[0016] The intake pipe 300 is a pipe for guiding air (outside air) to a cylinder of the engine 200, and is connected to the engine 200. The exhaust pipe 400 is a pipe for guiding exhaust gas discharged from the engine 200 to the outside of the vehicle, and is connected to the engine 200.

[0017] The refrigerant flow path 500 is a flow path for circulating a refrigerant for cooling the engine 200. Specifically, the refrigerant is an amine-based solution. The amine-based solution is an organic solvent having an amino group in its molecular structure. The amine-based solution includes, for example, solvents such as ethanolamine, monoethanolamine (MEA), methyldiethanolamine (MDEA), 2-amino-2-methyl-1-propanol (AMP), and piperazine (PZ). The amine-based solution according to this embodiment functions as a refrigerant (cooling liquid) for cooling the engine 200 and as a CO2 capture solution for capturing CO2 from exhaust gas. In this embodiment, the exhaust gas and the amine-based solution are mixed to dissolve the CO2 gas in the exhaust gas in the amine-based solution, and the CO2 gas is absorbed in the amine-based solution. The amine-based solution has a characteristic that the amount of CO2 absorbed changes depending on the temperature.

[0018] Specifically, the lower the temperature of the amine solution, the greater the amount of CO2 absorbed, and the higher the temperature, the smaller the amount of CO2 absorbed. The amine solution with dissolved CO2 releases the dissolved CO2 as the temperature increases.

[0019] The amine-based solution of this embodiment dissolves more CO2 when the temperature is, for example, 40°C or lower than when the temperature is 120°C or higher. In other words, the amine-based solution can absorb CO2 when the temperature is 40°C or lower and separate CO2 when the temperature is 120°C or higher. In this embodiment, the amine-based solution is heated to a predetermined temperature (for example, 120°C) or higher by heat exchange between the amine-based solution at a low temperature (for example, 40°C) as a refrigerant and the high-temperature engine. As a result, the CO2 dissolved in the amine-based solution is vaporized and CO2 gas is released from the amine-based solution, and the amine-based solution is separated into the amine-based solution (liquid phase) and CO2 gas (gas phase). As described later, the gas-liquid separator 800 separates the CO2 gas (gas phase) from the high-temperature amine-based solution (liquid phase).

[0020] The refrigerant flow path 500 of this embodiment includes a first refrigerant flow path 510, a second refrigerant flow path 520, a third refrigerant flow path 530, and a fourth refrigerant flow path 540. The first refrigerant flow path 510 connects the heat exchanger 700 and the mixer 600. A refrigerant pump 550 is provided in the first refrigerant flow path 510. The refrigerant pump 550 is a pump for circulating an amine-based solution, which is a refrigerant, through the first refrigerant flow path 510, the second refrigerant flow path 520, the third refrigerant flow path 530, and the fourth refrigerant flow path 540 in this order.

[0021] The refrigerant pump 550 may be provided in any location in the refrigerant flow path 500, and may be provided in, for example, the second refrigerant flow path 520, the third refrigerant flow path 530, or the fourth refrigerant flow path 540. The amine-based solution can be circulated in the refrigerant flow path 500 by the refrigerant pump 550.

[0022] The second refrigerant flow path 520 connects the mixer 600 and the engine 200. The third refrigerant flow path 530 connects the engine 200 and the gas-liquid separator 800. A part of the third refrigerant flow path 530 passes through a part of the engine body. The amine-based solution flowing through the third refrigerant flow path 530 exchanges heat with heat generated by the engine 200 and is heated while flowing through a part of the engine body. The engine body is cooled by exchanging heat with the amine-based solution flowing through the third refrigerant flow path 530. The fourth refrigerant flow path 540 connects the gas-liquid separator 800 and the heat exchanger 700.

[0023] The mixer 600 is provided at an intersection of the exhaust pipe 400 and the refrigerant flow path 500. The mixer 600 is connected to the first refrigerant flow path 510 and the second refrigerant flow path 520. The mixer 600 mixes the exhaust gas flowing through the exhaust pipe 400 with the amine-based solution flowing through the refrigerant flow path 500.

[0024] The mixer 600 is, for example, a mixer of a tank gas discharge type that makes the exhaust gas bubble and pass it from the bottom of a liquid tank in which an amine-based solution is stored. However, without being limited thereto, the mixer 600 may be a liquid phase separation type mixer that sprays the amine-based solution into the exhaust gas to absorb CO2 in the exhaust gas into the amine-based solution, and performs liquid phase separation using a cyclone or demister. The mixer 600 may also be a downcomer type mixer that absorbs CO2 in the exhaust gas into the amine-based solution in the process of dropping the amine-based solution from the top of the exhaust gas.

[0025] The heat exchanger 700 is provided upstream of the mixer 600 in the refrigerant flow path 500, and is provided between the mixer 600 and the gas-liquid separator 800. The heat exchanger 700 is connected to the first refrigerant flow path 510 and the fourth refrigerant flow path 540. The heat exchanger 700 cools the amine-based solution flowing through the refrigerant flow path 500 to a first temperature or lower (e.g., 40°C or lower) at which CO2 can be absorbed.

[0026] The gas-liquid separator 800 is provided in the refrigerant flow path 500 between the heat exchanger 700 and the engine 200. The gas-liquid separator 800 is connected to the third refrigerant flow path 530 and the fourth refrigerant flow path 540. The gas-liquid separator 800 separates the CO2 gas released from the amine-based solution by the heat of the engine 200.

[0027] The reflux pipe 900 connects the gas-liquid separator 800 and the intake pipe 300. The reflux pipe 900 introduces the CO2 gas separated in the gas-liquid separator 800 into the intake pipe 300.

[0028] The control device 1000 has one or more processors 1100 and one or more memories 1200 connected to the processor 1100. The processor 1100 includes, for example, a CPU (Central Processing Unit). The memory 1200 includes, for example, a ROM (Read Only Memory) and a RAM (Random Access Memory). The ROM is a storage element that stores programs and computation parameters used by the CPU. The RAM is a storage element that temporarily stores data such as variables and parameters used in processing executed by the CPU.

[0029] The control device 1000 communicates with each device (e.g., a refrigerant thermometer 1300, an exhaust flowmeter 1400, an intake flowmeter 1500, etc.) mounted on the vehicle 10. The refrigerant thermometer 1300 is provided in the refrigerant flow path 500 and measures the temperature of the amine-based solution flowing through the refrigerant flow path 500. In this embodiment, the refrigerant thermometer 1300 is provided in the first refrigerant flow path 510 and measures the temperature of the amine-based solution flowing upstream of the refrigerant pump 550. The exhaust flowmeter 1400 is provided in the exhaust pipe 400 and measures the flow rate of exhaust gas flowing through the exhaust pipe 400. The intake flowmeter 1500 is provided in the intake pipe 300 and measures the flow rate of intake gas flowing through the intake pipe 300. The communication between the control device 1000 and each device is realized, for example, by using CAN (Controller Area Network) communication.

[0030] The control device 1000 has a refrigerant pump control unit 1110. Various processes performed by the refrigerant pump control unit 1110 can be executed by the processor 1100. In detail, the processor 1100 executes a program stored in the memory 1200, thereby executing various processes.

[0031] The refrigerant pump control unit 1110 acquires information from the refrigerant thermometer 1300, the exhaust flow meter 1400, and the intake flow meter 1500. The refrigerant pump control unit 1110 controls the refrigerant pump 550 based on the information from the refrigerant thermometer 1300, the exhaust flow meter 1400, and the intake flow meter 1500. For example, the refrigerant pump control unit 1110 operates or stops the refrigerant pump 550 by controlling the power supply to the refrigerant pump 550. The refrigerant pump control unit 1110 also controls the rotation speed of the refrigerant pump 550 by controlling the current supplied to the refrigerant pump 550. The refrigerant pump control unit 1110 controls the flow rate of the amine-based solution flowing through the refrigerant flow passage 500 by controlling the rotation speed of the refrigerant pump 550. Specifically, the refrigerant pump control unit 1110 controls the flow rate of the amine-based solution based on the temperature of the amine-based solution, the flow rate of the exhaust gas, and the flow rate of the intake air so that the thermal efficiency of the engine 200 is maximized. In this embodiment, correlation data among the temperature of the amine-based solution, the flow rate of exhaust gas, the flow rate of intake air, the flow rate of the amine-based solution, and the thermal efficiency of the engine 200 is obtained in advance through experiments. The coolant pump control unit 1110 controls the flow rate of the amine-based solution based on the correlation data. For example, the coolant pump control unit 1110 controls the flow rate of the amine-based solution to be increased in accordance with an increase in the temperature of the amine-based solution, an increase in the flow rate of exhaust gas, and an increase in the flow rate of intake air.

[0032] The functions of the control device 1000 according to the present embodiment may be divided among multiple control devices, or multiple functions may be realized by one control device. When the functions of the control device 1000 are divided among multiple control devices, the multiple control devices may be connected to each other via a communication bus such as a CAN.

[0033] [2. Engine system operation] Next, the operation of the engine system 100 according to this embodiment will be described with reference to Fig. 1. The amine-based solution can be circulated within the coolant passage 500 by driving the coolant pump 550.

[0034] In the heat exchanger 700, the amine-based solution is cooled to a first temperature or lower (for example, 40° C. or lower), and the cooled amine-based solution is supplied by the refrigerant pump 550 from the heat exchanger 700 through the first refrigerant passage 510 to the mixer 600.

[0035] In the mixer 600, the amine-based solution is mixed with the exhaust gas flowing through the exhaust pipe 400. At this time, CO2 in the exhaust gas is dissolved in the amine-based solution. The mixer 600 mixes the amine-based solution with the exhaust gas, thereby causing the amine-based solution to absorb the CO2 gas contained in the exhaust gas.

[0036] The amine-based solution that has absorbed the CO2 gas is supplied to the engine 200 from the mixer 600 through the second refrigerant passage 520 by the refrigerant pump 550. The engine 200 heats the amine-based solution with heat generated by burning a mixture of fuel and air in the combustion chamber.

[0037] The engine 200 heats the amine-based solution to a second temperature or higher (e.g., 120° C. or higher) at which CO2 can be released from the amine-based solution. Here, the second temperature is a temperature higher than a first temperature (e.g., 40° C.) at which the amine-based solution can absorb CO2.

[0038] At this time, the amine-based solution is heated, and the CO2 gas dissolved in the amine-based solution is separated from the amine-based solution. The heated amine-based solution is supplied by the refrigerant pump 550 from the engine 200 through the third refrigerant passage 530 to the gas-liquid separator 800.

[0039] The gas-liquid separator 800 separates the CO2 gas released from the amine-based solution due to heating by the engine 200. The amine-based solution from which the CO2 gas has been separated is supplied by the refrigerant pump 550 from the gas-liquid separator 800 through the fourth refrigerant passage 540 to the heat exchanger 700.

[0040] The CO2 gas separated from the amine-based solution by the gas-liquid separator 800 is supplied from the gas-liquid separator 800 through a return pipe 900 to the intake pipe 300 and mixed with the intake air.

[0041] [4. Summary] As described above, according to this embodiment, the CO2 contained in the exhaust gas can be dissolved in the low-temperature amine-based solution by mixing the low-temperature amine-based solution and the exhaust gas in the mixer 600. At this time, the amine-based solution is cooled in the heat exchanger 700 to a first temperature or lower (for example, 40°C or lower) at which the CO2 gas can be absorbed, thereby increasing the amount of CO2 gas dissolved.

[0042] In addition, by supplying the engine 200 with a low-temperature amine-based solution in which CO2 is dissolved, the amine-based solution can be used as a coolant for the engine 200. At this time, heat exchange is performed between the amine-based solution and the engine 200, so that the engine 200 is cooled and the amine-based solution is heated to a second temperature or higher (for example, 120°C or higher). Specifically, the amine-based solution is heated in the engine 200 to a second temperature or higher (for example, 120°C or higher) that is higher than the first temperature (for example, 40°C) and allows the CO2 gas to be released. This allows the CO2 gas to be released from the high-temperature amine-based solution, and the high-temperature amine-based solution (liquid phase) and the CO2 gas (gas phase) to be separated. Note that the amine-based solution flowing through the coolant flow passage 500 can improve the heat exchange efficiency by directly exchanging heat with the engine 200 compared to the case of exchanging heat via general engine cooling water.

[0043] The CO2 gas released from the amine-based solution is separated from the amine-based solution by the gas-liquid separator 800. The CO2 gas separated by the gas-liquid separator 800 is guided to the intake pipe 300 via the return pipe 900 and mixed with the intake air (air) in the intake pipe 300.

[0044] This allows the nitrogen concentration in the intake air to be reduced by the amount of CO2 gas introduced into the intake air. Specifically, if nitrogen makes up 70% of the intake air components and an amount of CO2 gas that is about 40% of the amount of exhaust gas is mixed into the intake air, the nitrogen fraction in the mixed intake air can be reduced to about 42%. As a result, NOx is less likely to be generated by the combustion process of engine 200, and the amount of NOx emissions can be reduced.

[0045] In addition, CO2 has a lower specific heat ratio than oxygen or nitrogen. Therefore, compared to when CO2 gas is not mixed into the intake air, it is possible to suppress the temperature rise when compressed in the combustion chamber of the engine 200, and it is possible to suppress the phenomenon known as knocking.

[0046] Furthermore, NOx is usually purified by a three-way catalyst provided in the exhaust pipe 400. The three-way catalyst functions well under conditions of the stoichiometric air-fuel ratio of the engine 200, but does not function well under conditions such as lean burn.

[0047] According to this embodiment, since the nitrogen concentration in the intake air is reduced, it is possible to reduce the amount of NOx emissions after combustion even under conditions such as lean burn where the three-way catalyst does not function well.

[0048] Moreover, by controlling the coolant pump 550 by the coolant pump control unit 1110 based on the temperature of the amine solution, the flow rate of the exhaust gas, and the flow rate of the intake air, the thermal efficiency of the engine 200 can be improved.

[0049] [5. Second embodiment] Next, an engine system 2000 according to a second embodiment of the present invention will be described with reference to Fig. 2. Fig. 2 is a schematic configuration diagram showing the engine system 2000 according to the second embodiment of the present invention. Note that, with respect to the engine system 2000 according to the second embodiment, components substantially equivalent to those of the engine system 100 according to the first embodiment are denoted by the same reference numerals and detailed description thereof will be omitted.

[0050] As shown in FIG. 2, the engine system 2000 of the second embodiment includes a reflux pump 2100, a nitrogen separation membrane 2200, a supercharger 2300, an intake pressure gauge 1600, and a reflux pressure gauge 1700 in addition to the engine system 100 of the first embodiment.

[0051] The reflux pump 2100 is a pump for sending the CO2 gas separated by the gas-liquid separator 800 to the intake pipe 300. The reflux pump 2100 is provided in the reflux pipe 900. The reflux pump 2100 pumps the CO2 gas separated by the gas-liquid separator 800 to the intake pipe 300.

[0052] The nitrogen separation membrane 2200 is provided in the intake pipe 300, between the engine 200 and the supercharger 2300. The nitrogen separation membrane 2200 separates and removes nitrogen gas from the intake air flowing through the intake pipe 300.

[0053] The turbocharger 2300 is provided in the intake pipe 300, upstream of the nitrogen separation membrane 2200. In other words, the turbocharger 2300 is provided in the intake pipe 300, on the opposite side of the nitrogen separation membrane 2200 to the engine 200. The turbocharger 2300 increases the pressure of the intake air flowing through the intake pipe 300.

[0054] The processor 1100 of the second embodiment has a reflux pump control unit 1120 in addition to the refrigerant pump control unit 1110. The intake pressure gauge 1600 is electrically connected to the control device 1000 and measures the pressure of the intake air flowing through the intake pipe 300. The reflux pressure gauge 1700 is electrically connected to the control device 1000 and measures the pressure of the CO2 gas flowing through the reflux pipe 900.

[0055] The reflux pump control unit 1120 controls the reflux pump 2100 based on the measurement results of the intake pressure gauge 1600 and the reflux pressure gauge 1700. Specifically, the reflux pump control unit 1120 controls the CO2 gas pressure in the reflux pipe 900 so that the pressure of the CO2 gas in the intake pipe 300 between the nitrogen separation membrane 2200 and the engine 200 is greater than the pressure of the intake air in the intake pipe 300.

[0056] As described above, according to the second embodiment, nitrogen gas in the intake air can be separated and removed by providing the nitrogen separation membrane 2200 in the intake pipe 300. As the nitrogen concentration in the intake air decreases, NOx becomes less likely to be generated.

[0057] Furthermore, by providing the turbocharger 2300 upstream of the nitrogen separation membrane 2200, the pressure difference between the upstream and downstream sides of the nitrogen separation membrane 2200 can be increased. The greater this pressure difference, the higher the nitrogen gas separation efficiency of the nitrogen separation membrane 2200 can be. If the nitrogen gas in the intake air can be completely removed by the nitrogen separation membrane 2200, the intake air will contain only oxygen and CO2, making it possible to configure a closed-loop type heat engine in a combustion cycle using only oxygen and CO2.

[0058] In addition, by controlling the CO2 gas pressure using the reflux pump control unit 1120 so that the pressure in the reflux pipe 900 is greater than the pressure in the intake pipe 300, it is possible to make it easier to introduce the CO2 gas separated by the gas-liquid separator 800 into the intake pipe 300.

[0059] Although the embodiment of the present invention has been described above with reference to the attached drawings, it goes without saying that the present invention is not limited to such an embodiment. It is clear that a person skilled in the art can think of various modified or altered examples within the scope of the claims, and it is understood that such examples also naturally belong to the technical scope of the present invention.

[0060] In the above first and second embodiments, an example has been described in which the control device 1000 includes the refrigerant pump control unit 1110 and the reflux pump control unit 1120. However, the refrigerant pump control unit 1110 and the reflux pump control unit 1120 are not essential components, and may not be included in the control device 1000. [Explanation of symbols]

[0061] 10 Vehicles 100 Engine System 200 Engine 300 Intake pipe 400 exhaust pipe 500 Coolant flow path 510 First refrigerant flow path 520 Second refrigerant flow path 530 Third refrigerant flow path 540 Fourth refrigerant flow path 550 Refrigerant Pump 600 mixer 700 heat exchanger 800 Gas-liquid separator 900 Reflux tube 1000 Control device 1100 Processor 1110 Coolant pump control unit 1120 Circulation pump control unit 1200 Memory 1300 Refrigerant thermometer 1400 Exhaust Flow Meter 1500 Intake Flow Meter 1600 Intake Pressure Gauge 1700 Reflux pressure gauge 2000 Engine System 2100 Circulation Pump 2200 Nitrogen separation membrane 2300 Turbocharger

Claims

1. The engine, an intake pipe connected to the engine; an exhaust pipe connected to the engine; a coolant flow path through which a coolant for cooling the engine circulates; a mixer provided at an intersection between the exhaust pipe and the refrigerant flow path; a heat exchanger provided upstream of the mixer in the refrigerant flow path; a gas-liquid separator provided in the refrigerant flow path between the heat exchanger and the engine; a return pipe connecting the gas-liquid separator and the intake pipe; Equipped with The refrigerant flow path is a first refrigerant flow path connecting the heat exchanger and the mixer; a second refrigerant flow path connecting the mixer and the engine; a third refrigerant flow path connecting the engine and the gas-liquid separator; a fourth refrigerant flow path connecting the gas-liquid separator and the heat exchanger; Including, The refrigerant is an amine-based solution, The amine-based solution cooled by the heat exchanger is supplied from the heat exchanger through the first refrigerant flow path to the mixer; In the mixer, the amine-based solution cooled by the heat exchanger is mixed with the exhaust gas flowing through the exhaust pipe, thereby reducing CO ２ Absorbing the gas into the amine-based solution; The CO ２ The amine-based solution having absorbed the gas is supplied from the mixer through the second refrigerant passage to the engine; The amine-based solution heated by the engine is supplied from the engine through the third refrigerant flow path to the gas-liquid separator; In the gas-liquid separator, the amine-based solution is heated by the engine, and CO released from the amine-based solution due to the heating is removed. ２ Separating the gas, The gas-liquid separator ２ The amine-based solution from which the gas has been separated is supplied from the gas-liquid separator through the fourth refrigerant flow path to the heat exchanger; The CO separated from the amine-based solution by the gas-liquid separator ２ The gas is supplied from the gas-liquid separator through the return pipe to the intake pipe and mixed with the intake air. Engine system.

2. A supercharger provided in the intake pipe; A nitrogen separation membrane provided in the intake pipe between the engine and the turbocharger; The engine system of claim 1 , comprising:

3. A reflux pump provided in the reflux pipe; A reflux pump control unit that controls the reflux pump; Equipped with The reflux pump control unit is The pressure of the intake air in the intake pipe between the nitrogen separation membrane and the engine is higher than the pressure of the CO ２ The engine system according to claim 2 , wherein the reflux pump is controlled so that the pressure of the gas increases.

4. a refrigerant pump provided in the refrigerant flow path; A refrigerant pump control unit that controls the refrigerant pump; Equipped with The refrigerant pump control unit is 4. The engine system according to claim 1, wherein the coolant pump is controlled based on a temperature of the amine-based solution, a flow rate of the exhaust gas, and a flow rate of the intake air.

5. The amine-based solution is used to convert the CO ２ cooled below a first temperature at which the gas can be absorbed; The amine-based solution is provided in the engine at a temperature higher than the first temperature. ２ 5. The engine system according to claim 1, wherein the engine system is heated to a second temperature or higher at which the gas can be released.

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