Exhaust emission control system

Abstract

To provide an exhaust emission control system capable of reducing electric power consumption.SOLUTION: An exhaust emission control system includes: an adsorption / desorption section 310 (adsorption part) that can adsorb carbon dioxide and nitrogen oxide included in exhaust gas; a first cooling section (first cooling part 321 and third cooling part 323) that cools at least one of exhaust gas to be guided to the adsorption / desorption section 310, the adsorption / desorption section 310, or carbon dioxide desorbed from the adsorption / desorption section 310 by using a refrigerant in a liquid phase; and a second cooling section (second cooling part 322 and fourth cooling part 324) that cools at least one of the exhaust gas to be guided to the adsorption / desorption section 310, the adsorption / desorption section 310, or the carbon dioxide desorbed from the adsorption / desorption section 310 by using a refrigerant in a liquid phase flowing in a route independent of the first cooling section.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a technique for an exhaust gas purification system for purifying exhaust gas. [Background technology]

[0002] Conventionally, the technology of an exhaust gas purification system for purifying exhaust gas has been publicly known, as described in Patent Document 1, for example.

[0003] Patent Document 1 describes a carbon dioxide separation and capture system equipped with an adsorption and desorption module capable of adsorbing and desorbing carbon dioxide contained in a target gas such as exhaust gas. In this separation and capture system, in the adsorption step, the cooled target gas is supplied to the adsorption and desorption module, so that carbon dioxide can be separated from the target gas and adsorbed by the adsorbent. In the desorption step, the adsorbent is heated to a desorption temperature higher than the adsorption temperature, so that the carbon dioxide adsorbed by the adsorbent can be captured.

[0004] When adsorbing carbon dioxide into an adsorbent, it is necessary to cool the target gas and the adsorption / desorption module to a predetermined temperature. However, in order to cool the target gas, etc., power is required to operate various devices (e.g., a refrigeration cycle compressor, etc.), so technology that can reduce this power consumption is desired. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2021-159816 A Summary of the Invention [Problem to be solved by the invention]

[0006] One aspect of the present disclosure has been made in consideration of the above-mentioned circumstances, and a problem to be solved by the present disclosure is to provide an exhaust gas purification system that is capable of reducing power consumption. [Means for solving the problem]

[0007] The problem to be solved by the present invention has been described above, and the means for solving this problem will now be described.

[0008] An exhaust gas purification system according to one embodiment of the present disclosure includes an adsorption section capable of adsorbing carbon dioxide and nitrogen oxides contained in exhaust gas, a first cooling section that cools at least one of the exhaust gas guided to the adsorption section, the adsorption section, or the carbon dioxide desorbed from the adsorption section using a liquid phase refrigerant, and a second cooling section that cools at least one of the exhaust gas guided to the adsorption section, the adsorption section, or the carbon dioxide desorbed from the adsorption section using a liquid phase refrigerant that flows through a path independent of the first cooling section.

[0009] At least one of the first cooling section and the second cooling section includes a radiator that dissipates heat of the refrigerant.

[0010] The exhaust gas purification system also includes an auxiliary cooling section capable of cooling the refrigerant used in at least one of the first cooling section and the second cooling section by using a phase-change refrigerant.

[0011] In addition, the first cooling section cools the exhaust gas that is guided to the adsorption section, and the second cooling section cools the exhaust gas after it has been cooled by the first cooling section.

[0012] In addition, the first cooling section cools the exhaust gas guided to the adsorption section and heats the adsorption section using waste heat from the exhaust gas, and the second cooling section cools the adsorption section.

[0013] The exhaust gas purification system also includes a reduction section capable of performing reduction of nitrogen oxides in the adsorption section by using urea or a hydrocarbon as a reducing agent. Effect of the Invention

[0014] According to one aspect of the present disclosure, it is possible to reduce power consumption. [Brief description of the drawings]

[0015] [Figure 1] 1 is a schematic diagram showing a configuration of an exhaust gas purification system according to an embodiment of the present disclosure; [Diagram 2] FIG. 6 is a schematic diagram showing a configuration of an exhaust gas purification system according to another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] First, the configuration of an exhaust gas purification system 4 according to one aspect (embodiment) of the present disclosure will be described with reference to FIG.

[0017] The exhaust gas purification system 4 purifies carbon dioxide (CO2) and nitrogen oxides (NOx) contained in exhaust gas. In this embodiment, an exhaust gas purification system 4 that purifies exhaust gas discharged from an engine E will be described as an example. The exhaust gas purification system 4 mainly includes an adsorption / desorption section 310, a cooling section 320, an auxiliary cooling section 330, a storage section 340, a heating device 350, a control section 360, and the like.

[0018] The adsorption / desorption unit 310 adsorbs carbon dioxide (CO2) and nitrogen oxides (NOx) contained in the exhaust gas. The adsorption / desorption unit 310 is provided with a zeolite-based adsorbent such as Cu-ZSM-5. The zeolite-based adsorbent is a porous material, and the size of the pores affects the carbon dioxide absorption capacity, as described below. In addition, the metal supported by the zeolite-based adsorbent affects its performance as an SCR catalyst, as described below.

[0019] FIG. 1 illustrates the adsorption / desorption section 310 (adsorption / desorption section 310A on the upper and left side in the figure) in a state where it is heated by waste heat of the exhaust gas supplied by the first cooling section 321, the adsorption / desorption section 310 (adsorption / desorption section 310B on the lower and right side in the figure) in a state where it is cooled by the refrigerant of the second cooling section 322, the adsorption / desorption section 310 (adsorption / desorption section 310C on the upper and right side in the figure) in a state where it is heated (preheated) by the refrigerant that has passed through the adsorption / desorption section 310A, and the adsorption / desorption section 310 (adsorption / desorption section 310D) in a state where it is cooled (precooled) by the refrigerant of the second cooling section 322, the exhaust gas that has passed through the adsorption / desorption section 310B, and the outside air supplied by the fifth cooling section 325 described later.

[0020] In this manner, the exhaust gas purification system 4 according to this embodiment includes a plurality of (four) adsorption / desorption units 310, and when one adsorption / desorption unit 310A is heated, another adsorption / desorption unit 310C is preheated, and when another adsorption / desorption unit 310B is adsorbing carbon dioxide or the like, another adsorption / desorption unit 310D is precooled, and so on. In this manner, the processes by each adsorption / desorption unit 310 can be performed in parallel. Furthermore, by appropriately switching the flow paths of the exhaust gas, the refrigerant, and the like, the state of each adsorption / desorption unit 310 (adsorption / desorption units 310A to 310D) can be arbitrarily switched. For example, each adsorption / desorption unit 310 can be switched in the following order: a state in which carbon dioxide or the like is adsorbed (adsorption / desorption unit 310B), a preheated state (adsorption / desorption unit 310C), a state in which carbon dioxide is desorbed by heating (adsorption / desorption unit 310A), and a precooled state (adsorption / desorption unit 310D). By sequentially switching the state of each adsorption / desorption unit 310 in this manner, it is possible to sequentially perform adsorption and desorption of carbon dioxide and the like, reduction of nitrogen oxides, and the like in each adsorption / desorption unit 310.

[0021] In addition to the above four states, when reducing the nitrogen oxides adsorbed in the adsorption / desorption section 310, the adsorption / desorption section 310 can be temporarily heated to a temperature higher than the state in which carbon dioxide is desorbed (adsorption / desorption section 310A). By supplying a reducing agent together with exhaust gas to the adsorption / desorption section 310 in this state (in this embodiment, adsorption / desorption section 310B), the nitrogen oxides adsorbed in the adsorption / desorption section 310 can be reduced.

[0022] Specifically, exhaust gas from the engine E is guided to the adsorption / desorption unit 310 (adsorption / desorption unit 310B) via a path L11 formed of piping or the like. A reducing agent can be injected from an injection device 311 into the exhaust gas supplied to the adsorption / desorption unit 310B via the path L11. As the reducing agent, urea or hydrocarbon can be used. For example, when urea is used as the reducing agent, urea water stored in a tank can be injected by the injection device 311. The injected urea water is thermally decomposed by the waste heat of the exhaust gas, and ammonia is generated. This ammonia acts as a reducing agent. When hydrocarbons are used as the reducing agent, hydrocarbons generated by decomposition of diesel fuel can be used. Furthermore, the exhaust gas whose temperature has been reduced by passing through the adsorption / desorption unit 310B is supplied to the adsorption / desorption unit 310D via a path L12, and the adsorption / desorption unit 310D can be cooled. The exhaust gas that has cooled the adsorption / desorption unit 310D is then discharged to the outside via a path L13.

[0023] The cooling section 320 uses a refrigerant to cool the exhaust gas and each section of the exhaust gas purification system 4. The cooling section 320 mainly includes a first cooling section 321, a second cooling section 322, a third cooling section 323, a fourth cooling section 324, and a fifth cooling section 325. Note that the first cooling section 321 and the third cooling section 323, as well as the second cooling section 322 and the fourth cooling section 324, share a part of the refrigerant flow path. A specific description will be given below.

[0024] The first cooling section 321 uses a refrigerant to cool the exhaust gas discharged from the engine E, and also uses waste heat from the exhaust gas to heat the adsorption / desorption section 310. As the refrigerant, for example, a liquid-phase fluid having a relatively large heat capacity (for example, cooling water or oil) can be used. The first cooling section 321 mainly includes a circulation path L21, a heat exchanger 321a, a radiator 321b, a pump 321c, and a heat exchanger 321d.

[0025] The circulation path L21 is configured by piping or the like, and allows the refrigerant to flow through it. The circulation path L21 is formed to sequentially connect the heat exchanger 321a, the adsorption / desorption unit 310A, the adsorption / desorption unit 310C, the heat exchanger 321d, the radiator 321b, and the pump 321c.

[0026] The heat exchanger 321a is provided in the middle of the path L11. The heat exchanger 321a exchanges heat between the exhaust gas discharged from the engine E and the refrigerant, thereby lowering the temperature of the exhaust gas. The refrigerant that has received the heat of the exhaust gas in the heat exchanger 321a is supplied to the adsorption / desorption section 310 (adsorption / desorption section 310A). This makes it possible to heat the adsorption / desorption section 310A. By heating the adsorption / desorption section 310A, the carbon dioxide adsorbed in the adsorption / desorption section 310A can be desorbed.

[0027] The refrigerant that has passed through the adsorption / desorption unit 310A is further supplied to the adsorption / desorption unit 310C. This allows the adsorption / desorption unit 310C to be preheated. The preheated adsorption / desorption unit 310C is later switched to the adsorption / desorption unit 310A by switching the flow path of the refrigerant, etc. The refrigerant that has passed through the adsorption / desorption unit 310C is cooled by the heat exchanger 321d.

[0028] Water from a storage section 321e capable of storing water is appropriately supplied to the heat exchanger 321d by a pump (not shown). In the heat exchanger 321d, heat exchange is performed between the water supplied from the storage section 321e and the refrigerant that has passed through the adsorption / desorption section 310C, thereby cooling the refrigerant. The water stored in the storage section 321e is condensed water generated in the heat exchanger 321a that exchanges heat with the exhaust gas and the heat exchanger 323a of the third cooling section 323 described later.

[0029] The refrigerant that has passed through the heat exchanger 321d is further supplied to the pump 321c after heat is dissipated by the radiator 321b. The refrigerant supplied to the pump 321c is supplied again to the heat exchanger 321a by the pump 321c.

[0030] In this manner, the first cooling section 321 can cool the exhaust gas by circulating the refrigerant, and can also heat the adsorption / desorption section 310 by utilizing the waste heat of the exhaust gas.

[0031] The second cooling section 322 is for cooling the adsorption / desorption section 310B and the adsorption / desorption section 310D by using a refrigerant. The second cooling section 322 mainly includes a circulation path L22, a radiator 322a, and a pump 322b.

[0032] The circulation path L22 is composed of piping or the like, and allows the refrigerant to flow through it. The circulation path L22 is formed to sequentially connect the adsorption / desorption section 310B, the adsorption / desorption section 310D, the radiator 322a, the auxiliary cooling section 330, and the pump 322b. The circulation path L22 is formed independently of the circulation path L21 of the first cooling section 321. That is, the refrigerant used in the circulation path L21 (first cooling section 321) and the refrigerant used in the circulation path L22 (second cooling section 322) are independent of each other, and are not mixed. The circulation path L22 branches at a branching section P3 provided upstream of the adsorption / desorption section 310B and the adsorption / desorption section 310D, and is connected to the adsorption / desorption section 310B and the adsorption / desorption section 310D, respectively. The circulation path L21 branched off at the branch point P3 joins again at a branch point P4 provided downstream of the adsorption / desorption section 310B and the adsorption / desorption section 310D.

[0033] In the second cooling section 322, the refrigerant pumped from the pump 322b is supplied to the adsorption / desorption section 310B and the adsorption / desorption section 310D via the branching section P6 and the branching section P3. This allows the adsorption / desorption section 310B and the adsorption / desorption section 310D to be cooled. The refrigerant that has passed through the adsorption / desorption section 310B and the adsorption / desorption section 310D is supplied to the radiator 322a via the branching section P4. The refrigerant whose temperature has increased due to the heat of the adsorption / desorption section 310B and the adsorption / desorption section 310D is dissipated by the radiator 322a, and then supplied to the pump 322b via the auxiliary cooling section 330. The refrigerant supplied to the pump 322b is again supplied to the adsorption / desorption section 310B and the adsorption / desorption section 310D by the pump 322b.

[0034] In this manner, the secondary cooling section 322 can cool the adsorption / desorption section 310B and the adsorption / desorption section 310D by circulating the refrigerant.

[0035] The third cooling section 323 uses a refrigerant to cool carbon dioxide to be supplied to the storage section 340 described below. The third cooling section 323 mainly includes a circulation path L23, a heat exchanger 323a, a radiator 321b, a pump 321c, and a heat exchanger 321d. The third cooling section 323 uses the same refrigerant as the first cooling section 321. The third cooling section 323 also uses the radiator 321b, the pump 321c, and the heat exchanger 321d that are the same as those of the first cooling section 321.

[0036] The circulation path L23 is composed of piping or the like, and allows the refrigerant to flow through it. The circulation path L23 is formed to sequentially connect the heat exchanger 323a, the heat exchanger 321d, the radiator 321b, and the pump 321c. The circulation path L23 is formed to branch off from a branch point P1 formed downstream of the pump 321c in the circulation path L21, and a branch point P2 formed between the adsorption / desorption section 310C and the heat exchanger 321d in the circulation path L21. In this way, a part of the circulation path L21 of the first cooling section 321 (a part from the branch point P2 to the branch point P1) forms a part of the circulation path L23 of the third cooling section 323.

[0037] The heat exchanger 323a is provided in the middle of the circulation path L22 (downstream of the branching point P1). The heat exchanger 323a exchanges heat between the carbon dioxide supplied to the storage section 340 (described later) and the refrigerant flowing through the circulation path L23, and can lower the temperature of the carbon dioxide. The refrigerant that has received heat from the carbon dioxide in the heat exchanger 323a is cooled in the heat exchanger 321d, dissipates heat in the radiator 321b, and is then supplied to the pump 321c. The refrigerant supplied to the pump 321c is again supplied to the heat exchanger 323a by the pump 321c.

[0038] In this manner, the third cooling section 323 can cool the carbon dioxide supplied to the storage section 340 by circulating the same refrigerant as the first cooling section 321 .

[0039] The fourth cooling section 324 uses a refrigerant to further cool the exhaust gas cooled by the first cooling section 321. The fourth cooling section 324 mainly includes a circulation path L24, a heat exchanger 324a, a radiator 322a, and a pump 322b. The fourth cooling section 324 uses the same refrigerant as the second cooling section 322. The fourth cooling section 324 also uses the radiator 322a and pump 322b as the second cooling section 322.

[0040] The circulation path L24 is composed of piping or the like, and allows the refrigerant to flow. The circulation path L24 is formed to sequentially connect the radiator 322a, the auxiliary cooling unit 330, the pump 322b, and the heat exchanger 324a. The circulation path L24 is formed to branch off from a branch point P6 formed downstream of the pump 322b in the circulation path L22, and a branch point P5 formed between the adsorption / desorption unit 310B and the branch point P4 in the circulation path L22. In this way, a part of the circulation path L22 of the second cooling unit 322 (a part from the branch point P5 through the branch point P4, the radiator 322a, and the pump 322b to the branch point P6) constitutes a part of the circulation path L24 of the fourth cooling unit 324.

[0041] The heat exchanger 324a is provided in the middle of the circulation path L24 (downstream of the branch point P6). The heat exchanger 324a exchanges heat between the exhaust gas cooled by the heat exchanger 321a of the first cooling section 321 and flowing through the path L11 and the refrigerant, thereby further lowering the temperature of the exhaust gas. The refrigerant that has received the heat of the exhaust gas in the heat exchanger 324a is dissipated in the radiator 322a and then supplied to the pump 322b via the auxiliary cooling section 330. The refrigerant supplied to the pump 322b is supplied again to the heat exchanger 324a by the pump 322b.

[0042] In this manner, the fourth cooling section 324 can further cool the exhaust gas by circulating the coolant.

[0043] The fifth cooling unit 325 is for cooling the adsorption / desorption unit 310D by using a gas (air in this embodiment). The fifth cooling unit 325 mainly includes a path L25 and a pump 325a.

[0044] The path L25 is configured by a pipe or the like, and allows gas to flow through it. The path L25 is formed to sequentially connect the pump 325a and the adsorption / desorption unit 310D. The upstream end of the path L25 is open to the outside space, and external air (outside air) can be introduced.

[0045] The air introduced from the outside by the pump 325a flows through the adsorption / desorption unit 310D and is released to the outside. At this time, the air passing through the adsorption / desorption unit 310D can cool the adsorption / desorption unit 310D.

[0046] The auxiliary cooling section 330 is for auxiliary cooling the refrigerant used in the cooling section 320 (particularly, the second cooling section 322 and the fourth cooling section 324). The auxiliary cooling section 330 is a refrigeration cycle that performs cooling by changing the phase of an appropriate refrigerant (e.g., carbon dioxide, etc.). The auxiliary cooling section 330 mainly includes a heat exchanger 331, a compressor 332, a condenser 333, an expansion valve 334, etc.

[0047] The heat exchanger 331 is disposed between the radiator 322a and the pump 322b on the refrigerant circulation path (circulation path L22, circulation path L24). The heat exchanger 331 exchanges heat with the refrigerant circulating through the path, and can further lower the temperature of the refrigerant cooled by the radiator 322a. The refrigerant such as carbon dioxide used for heat exchange in the heat exchanger 331 is compressed by the compressor 332, and then dissipates heat in the condenser 333. The refrigerant that has dissipated heat in the condenser 333 can be supplied again to the heat exchanger 331 via the expansion valve 334.

[0048] For example, when the cooling capacity of the second cooling section 322 and the fourth cooling section 324 is insufficient with the radiator 322a alone (such as when it is necessary to cool the exhaust gas from the engine E to a temperature lower than the outside air temperature), the auxiliary cooling section 330 configured as described above can be operated to further cool the refrigerant in the second cooling section 322 and the fourth cooling section 324, thereby improving the cooling capacity.

[0049] The storage section 340 stores the carbon dioxide desorbed from the adsorption / desorption section 310A. The storage section 340 is connected to the adsorption / desorption section 310A via a path L14 configured by piping or the like. A compressor 341 and a heat exchanger 323a are provided in the middle of the path L14. The carbon dioxide desorbed from the adsorption / desorption section 310A is compressed by the compressor 341, has heat dissipated in the heat exchanger 323a, and is stored in the storage section 340.

[0050] The heating device 350 is a device for heating the adsorption / desorption unit 310. The heating device 350 can be configured with, for example, an electric heating wire. The temperature of the adsorption / desorption unit 310 can be detected by a temperature sensor 351. By controlling the operation of the heating device 350 and the like while detecting the temperature of the adsorption / desorption unit 310 with the temperature sensor 351, the temperature of the adsorption / desorption unit 310 can be adjusted to an arbitrary temperature.

[0051] The control unit 360 controls the operation of the exhaust gas purification system 4. The control unit 360 is composed of an arithmetic processing device such as a CPU, and a storage device such as a RAM, a ROM, and a HDD. The control unit 360 can receive the detection result of the temperature sensor 351. The control unit 360 can also control the heating device 350. However, the control unit 360 is not limited to this and can also control the operation of each part of the exhaust gas purification system 4.

[0052] Although detailed explanation is omitted, the flow path of the fluid in the exhaust gas purification system 4 (for example, carbon dioxide adsorbed and desorbed in the adsorption / desorption section 310) can be arbitrarily switched using a switching device (piping, switching valve, etc.) not shown.

[0053] The exhaust gas purification system 4 configured in this manner can be used to purify carbon dioxide and nitrogen oxides contained in the exhaust gas discharged from the engine E. A specific description will be given below.

[0054] First, the purification of carbon dioxide and nitrogen oxides contained in exhaust gas will be described.

[0055] In this case, the exhaust gas discharged from the engine E is cooled to a predetermined first temperature T1 (for example, about the outside air temperature (25 degrees)) by the first cooling section 321 and the fourth cooling section 324 while flowing through the path L11. The cooled exhaust gas is supplied to the adsorption / desorption section 310B, and carbon dioxide and nitrogen oxides in the exhaust gas are adsorbed by the adsorbent. In this way, by cooling the exhaust gas supplied to the adsorption / desorption section 310B by the first cooling section 321 and the fourth cooling section 324, the carbon dioxide and nitrogen oxides in the exhaust gas can be efficiently adsorbed.

[0056] If further cooling of the exhaust gas is required (if it is desired to lower the exhaust gas temperature below the outside air temperature), the auxiliary cooling unit 330 is operated. When the auxiliary cooling unit 330 is operated, the refrigeration cycle of the auxiliary cooling unit 330 lowers the temperature of the refrigerant in the fourth cooling unit 324, and the exhaust gas can be cooled to an even lower temperature. For example, by cooling the exhaust gas to about 0 degrees, the moisture in the exhaust gas can also be effectively removed.

[0057] The exhaust gas in which carbon dioxide and nitrogen oxides are adsorbed in the adsorption / desorption section 310B is supplied to the adsorption / desorption section 310D via the path L12. As a result, the adsorption / desorption section 310D can be cooled using the exhaust gas that has been cooled when passing through the adsorption / desorption section 310B. In this manner, in this embodiment, the adsorption / desorption section 310D can be cooled (pre-cooled) using the exhaust gas that has passed through the adsorption / desorption section 310B in addition to the second cooling section 322 and the fifth cooling section 325. As a result, the power consumption of the second cooling section 322 and the fifth cooling section 325 can be reduced. The exhaust gas that has passed through the adsorption / desorption section 310D is discharged to the outside via the path L13.

[0058] Next, the case where the carbon dioxide adsorbed in the adsorption / desorption section 310 is desorbed will be described.

[0059] In this case, waste heat of the exhaust gas recovered by the heat exchanger 321a of the first cooling section 321 is supplied to the adsorption / desorption section 310A via the refrigerant, and the adsorption / desorption section 310A is heated to a temperature higher than the first temperature T1. The adsorption / desorption section 310A is heated to a predetermined second temperature T2 (for example, about 150 degrees) at which carbon dioxide can be desorbed. At this time, the adsorption / desorption section 310 can also be heated using the heating device 350. This causes carbon dioxide to be desorbed from the adsorption / desorption section 310A. The carbon dioxide released from the adsorption / desorption section 310A is stored in the storage section 340 via a path L14.

[0060] Next, the case where the nitrogen oxides adsorbed in the adsorption / desorption unit 310 are reduced will be described.

[0061] In this case, the adsorption / desorption unit 310B is heated to a temperature higher than the second temperature T2 when carbon dioxide is desorbed. The adsorption / desorption unit 310 is heated to a predetermined third temperature T3 (for example, about 400 degrees) at which the adsorption / desorption unit 310 can function as an SCR catalyst. For this heating, first, waste heat of the exhaust gas recovered by the heat exchanger 321a of the first cooling unit 321 is used. The adsorption / desorption unit 310A and the adsorption / desorption unit 310C can be heated by this waste heat. If this waste heat is not sufficient, the heating device 350 is operated to heat the adsorption / desorption unit 310 to the target temperature. The heated adsorption / desorption unit 310A and the adsorption / desorption unit 310C are switched to the adsorption / desorption unit 310B.

[0062] A reducing agent is sprayed onto the exhaust gas supplied to the adsorption / desorption section 310B via path L11. As the exhaust gas passes through the adsorption / desorption section 310B, the nitrogen oxides adsorbed in the adsorption / desorption section 310B are reduced. The exhaust gas that has passed through the adsorption / desorption section 310B is discharged to the outside via paths L12 and L13.

[0063] The temperature of the adsorption / desorption section 310 and the flow paths of the fluids in each section can be switched by the control section 360. By switching the temperature of the adsorption / desorption section 310 to any one of the first temperature T1, the second temperature T2, and the third temperature T3 by the control section 360 and appropriately injecting a reducing agent from the injection device 311, it is possible to perform adsorption of carbon dioxide and nitrogen oxides, desorption of carbon dioxide, and reduction of nitrogen oxides using the common adsorption / desorption section 310. This eliminates the need to separately provide a purification device for purifying carbon dioxide and a purification device for purifying nitrogen oxides, thereby simplifying the configuration of the exhaust gas purification system 4.

[0064] In this embodiment, the exhaust gas, the adsorption / desorption section 310, and the like are cooled by a plurality of cooling sections (the first cooling section 321 and the third cooling section 323, and the second cooling section 322 and the fourth cooling section 324) having paths independent of each other. This prevents, for example, a refrigerant that has become hot in one cooling section from mixing with the path of the other cooling section and reducing the cooling capacity of the cooling section, thereby reducing the power consumption for cooling.

[0065] In this embodiment, the exhaust gas and the adsorption / desorption section 310 are cooled by the cooling section 320 that mainly uses a liquid-phase refrigerant. This makes it possible to reduce the use of equipment that consumes a large amount of power (such as a compressor). In this embodiment, the fifth cooling section 325 cools the adsorption / desorption section 310 using outside air. This makes it possible to further reduce power consumption. Furthermore, when the cooling capacity is insufficient, the auxiliary cooling section 330 can be used to temporarily improve the cooling capacity.

[0066] As described above, the exhaust gas purification system 4 according to one embodiment of the present disclosure has the following features: an adsorption / desorption unit 310 (adsorption unit) capable of adsorbing carbon dioxide and nitrogen oxides contained in exhaust gas; a first cooling section (a first cooling section 321 and a third cooling section 323) that uses a refrigerant to cool at least one of the exhaust gas guided to the adsorption / desorption section 310, the adsorption / desorption section 310, or the carbon dioxide desorbed from the adsorption / desorption section 310; a second cooling section (a second cooling section 322 and a fourth cooling section 324) that cools at least one of the exhaust gas guided to the adsorption / desorption section 310, the adsorption / desorption section 310, or the carbon dioxide desorbed from the adsorption / desorption section 310, using a refrigerant that flows through a path independent of the first cooling section; It is equipped with the following. This configuration can reduce power consumption. In other words, by separating the refrigerant flow paths of the first cooling section and the second cooling section, the refrigerant that has become hot in one cooling section does not reduce the cooling capacity of the other cooling section, so that the power consumption for cooling can be reduced.

[0067] In addition, the first cooling unit (first cooling unit 321) Cooling the exhaust gas guided to the adsorption / desorption unit 310 (the adsorption / desorption unit 310B and the adsorption / desorption unit 310D), The second cooling section (fourth cooling section 324) The cooling section cools the exhaust gas after it has been cooled by the first cooling section. This configuration can reduce power consumption. In other words, by separating the refrigerant flow paths of the first cooling section, where the refrigerant is relatively hot, from the second cooling section, where the refrigerant is relatively cold, it is possible to prevent a decrease in the cooling capacity of the second cooling section, and thus reduce power consumption.

[0068] In addition, the first cooling unit (first cooling unit 321) The exhaust gas guided to the adsorption units (adsorption / desorption unit 310B and adsorption / desorption unit 310D) is cooled, and the adsorption units (adsorption / desorption unit 310A and adsorption / desorption unit 310C) are heated using waste heat of the exhaust gas. The second cooling section (second cooling section 322) is This cools the adsorption parts (adsorption / desorption part 310B and adsorption / desorption part 310D). This configuration can reduce power consumption. In other words, by separating the refrigerant flow paths of the first cooling section, where the refrigerant is relatively hot, from the second cooling section, where the refrigerant is relatively cold, it is possible to prevent a decrease in the cooling capacity of the second cooling section, and thus reduce power consumption.

[0069] In addition, the first cooling section (the first cooling section 321 and the third cooling section 323) The exhaust gas guided to the adsorption section (adsorption / desorption section 310B and adsorption / desorption section 310D) and the carbon dioxide desorbed from the adsorption section (adsorption / desorption section 310A) are cooled, and the adsorption section (adsorption / desorption section 310A and adsorption / desorption section 310C) is heated using waste heat of the exhaust gas, The second cooling section (the second cooling section 322 and the fourth cooling section 324) It cools the exhaust gas cooled by the first cooling section, and the adsorption section (the adsorption / desorption section 310B and the adsorption / desorption section 310D). This configuration can reduce power consumption. In other words, by separating the refrigerant flow paths of the first cooling section, where the refrigerant is relatively hot, from the second cooling section, where the refrigerant is relatively cold, it is possible to prevent a decrease in the cooling capacity of the second cooling section, and thus reduce power consumption.

[0070] In addition, the exhaust gas purification system 4 is The cooling unit is provided with a condensed water cooling unit (storage unit 321e and heat exchanger 321d) that uses condensed water generated in the first cooling unit (first cooling unit 321 and third cooling unit 323) or the second cooling unit (second cooling unit 322 and fourth cooling unit 324) to cool the refrigerant used in at least one of the first cooling unit or the second cooling unit. With this configuration, the refrigerant is cooled using condensed water, so that the power consumption for cooling can be reduced.

[0071] In addition, the exhaust gas purification system 4 is The adsorption unit (adsorption / desorption unit 310D) is provided with an outside air cooling unit (fifth cooling unit 325) that cools the adsorption unit (adsorption / desorption unit 310D) by using outside air. With this configuration, the adsorption / desorption part 310D can be cooled using outside air, thereby reducing the power consumption for cooling.

[0072] In addition, the exhaust gas purification system 4 is The device includes an injection device 311 (reduction section) capable of reducing nitrogen oxides in the adsorption / desorption section 310 by using urea or a hydrocarbon as a reducing agent. With this configuration, the nitrogen oxides adsorbed in the adsorption / desorption section 310 can be reduced (purified), and the decrease in the adsorption capacity of the adsorption / desorption section 310 can be suppressed.

[0073] As described above, the exhaust gas purification system 4 according to one embodiment of the present disclosure has the following features: an adsorption / desorption unit 310 (adsorption unit) capable of adsorbing carbon dioxide and nitrogen oxides contained in exhaust gas; a first cooling section (a first cooling section 321 and a third cooling section 323) that cools at least one of the exhaust gas guided to the adsorption / desorption section 310, the adsorption / desorption section 310, or the carbon dioxide desorbed from the adsorption / desorption section 310, using a liquid-phase refrigerant; a second cooling section (a second cooling section 322 and a fourth cooling section 324) that cools at least one of the exhaust gas guided to the adsorption / desorption section 310, the adsorption / desorption section 310, or the carbon dioxide desorbed from the adsorption / desorption section 310, using a liquid-phase refrigerant that flows through a path independent of the first cooling section; It is equipped with the following. With this configuration, it is possible to reduce power consumption. That is, by separating the refrigerant flow paths of the first cooling section and the second cooling section, for example, a refrigerant that has become hot in one cooling section does not reduce the cooling capacity of the other cooling section, so that it is possible to reduce power consumption for cooling. Furthermore, since cooling is performed without using a cooling system (such as a refrigeration cycle) that involves a phase change of the refrigerant, equipment used in a refrigeration cycle (such as a compressor) is not required, and power consumption can be reduced. In particular, by using a liquid-phase refrigerant with a relatively large heat capacity, it is possible to achieve stable cooling performance while reducing power consumption.

[0074] In addition, at least one of the first cooling unit and the second cooling unit is The radiator includes a radiator (radiator 321b and radiator 322a) for dissipating heat from the refrigerant. With this configuration, the first refrigerant can be cooled while relatively reducing power consumption.

[0075] In addition, the exhaust gas purification system 4 is The cooling device includes an auxiliary cooling section 330 capable of cooling the refrigerant used in at least one of the first cooling section and the second cooling section by using a refrigerant that changes phase. By configuring in this manner, when the cooling capacity of the cooling section 320 is insufficient (for example, when it is desired to cool the exhaust gas to a temperature lower than the outside air temperature), the auxiliary cooling section 330 can be operated to improve the cooling capacity.

[0076] In addition, the first cooling unit (first cooling unit 321) Cooling the exhaust gas guided to the adsorption / desorption unit 310 (the adsorption / desorption unit 310B and the adsorption / desorption unit 310D), The second cooling section (fourth cooling section 324) The cooling section cools the exhaust gas after it has been cooled by the first cooling section. With this configuration, it is possible to reduce power consumption.

[0077] In addition, the first cooling unit (first cooling unit 321) The exhaust gas guided to the adsorption units (adsorption / desorption unit 310B and adsorption / desorption unit 310D) is cooled, and the adsorption units (adsorption / desorption unit 310A and adsorption / desorption unit 310C) are heated using waste heat of the exhaust gas. The second cooling section (second cooling section 322) is This cools the adsorption parts (adsorption / desorption part 310B and adsorption / desorption part 310D). With this configuration, it is possible to reduce power consumption.

[0078] As described above, the exhaust gas purification system 4 according to one embodiment of the present disclosure has the following features: A plurality of adsorption / desorption units 310 (adsorption units) capable of adsorbing carbon dioxide and nitrogen oxides contained in exhaust gas; a first cooling section (a first cooling section 321 and a third cooling section 323) that uses a refrigerant to cool at least one of the exhaust gas guided to the adsorption / desorption section 310, the adsorption / desorption section 310, or the carbon dioxide desorbed from the adsorption / desorption section 310; a second cooling section (a second cooling section 322 and a fourth cooling section 324) that cools at least one of the exhaust gas guided to the adsorption / desorption section 310, the adsorption / desorption section 310, or the carbon dioxide desorbed from the adsorption / desorption section 310, using a refrigerant that flows through a path independent of the first cooling section; a guide section (path L12) capable of guiding exhaust gas that has passed through one adsorption / desorption section 310 (adsorption / desorption section 310B) among the plurality of adsorption / desorption sections 310 to another adsorption / desorption section 310 (adsorption / desorption section 310D), thereby adjusting the temperature of the other adsorption / desorption section 310D; It is equipped with the following. By configuring in this way, it is possible to reduce the power consumption. That is, by making the flow paths of the refrigerant of the first cooling section and the second cooling section independent, for example, the refrigerant that has become hot in one cooling section does not reduce the cooling capacity of the other cooling section, so that it is possible to reduce the power consumption for cooling. In addition, the exhaust gas that has passed through the adsorption / desorption section 310B can be used to adjust the temperature of the other adsorption / desorption section 310D (cooling in the embodiment of the present disclosure), so that it is possible to reduce the power consumption of the second cooling section 322 for cooling the adsorption / desorption section 310D.

[0079] In addition, the plurality of adsorption / desorption units 310 are It is switchable between a first state (adsorption / desorption section 310B) in which carbon dioxide and nitrogen oxides are adsorbed, and a second state (adsorption / desorption section 310D) in which the first state is pre-cooled, The guide section (path L12) is The exhaust gas that has passed through the adsorption / desorption section 310B in the first state is guided to the adsorption / desorption section 310D in the second state. Such a configuration can reduce power consumption. That is, the adsorption / desorption unit 310D can be pre-cooled using the cold energy of the exhaust gas that has passed through the adsorption / desorption unit 310B, so that the power consumption of the secondary cooling unit 322 for cooling the adsorption / desorption unit 310D can be reduced.

[0080] In addition, the second cooling section (second cooling section 322) At least one of the adsorption / desorption section 310B in the first state and the adsorption / desorption section 310D in the second state is cooled using a liquid phase refrigerant. This configuration makes it possible to reduce power consumption. In other words, since cooling is performed without using a cooling system (such as a refrigeration cycle) that involves a phase change of the refrigerant, equipment used in a refrigeration cycle (such as a compressor) is not required, and power consumption can be reduced.

[0081] In addition, the plurality of adsorption / desorption units 310 are The adsorption / desorption unit 310A is switchable between a third state in which carbon dioxide is desorbed (adsorption / desorption unit 310A) and a fourth state in which the adsorption / desorption unit 310C is preheated before entering the third state (adsorption / desorption unit 310C). The first cooling section (first cooling section 321) is The exhaust gas guided to the adsorption sections (adsorption / desorption section 310B and adsorption / desorption section 310D) is cooled, and the waste heat of the exhaust gas is used to heat the adsorption section in the third state (adsorption / desorption section 310A) and the adsorption section in the fourth state (adsorption / desorption section 310C). Such a configuration can reduce power consumption. That is, the adsorption section (the adsorption / desorption section 310A and the adsorption / desorption section 310C) can be heated by effectively utilizing the waste heat of the exhaust gas, so that the power consumption for heating can be reduced.

[0082] The adsorption / desorption unit 310 according to this embodiment is one embodiment of an adsorption unit. Moreover, the first cooling section 321 and the third cooling section 323 according to this embodiment are an embodiment of the first cooling section. Moreover, the second cooling section 322 and the fourth cooling section 324 according to this embodiment are an embodiment of the second cooling section. The reservoir 321e and the heat exchanger 321d according to this embodiment are an embodiment of a condensed water cooling section. Moreover, the fifth cooling section 325 according to this embodiment is one embodiment of an outside air cooling section. Moreover, the injection device 311 according to this embodiment is one embodiment of the reduction section according to the present invention. Moreover, the path L12 according to this embodiment is one embodiment of a guide section according to the present invention.

[0083] Although one embodiment of the present invention has been described above, the present invention is not limited to the above configuration, and various modifications are possible within the scope of the invention described in the claims.

[0084] For example, the exhaust gas purification system 4 according to the above embodiment can be mounted on vehicles such as trucks and tractors. The exhaust gas purification system 4 can also be mounted on other work vehicles, agricultural vehicles, industrial vehicles, transport equipment, and the like.

[0085] In addition, the exhaust gas purification system 4 and the like according to the above embodiment have been described as purifying the exhaust gas discharged from the engine E, but the present invention is not limited to this and can be used for any purpose. For example, it is possible to purify exhaust gas discharged from boilers and gas turbines of thermal power plants and the like, and exhaust gas generated in steelworks and the like.

[0086] As described above, it is also possible to provide a plurality of adsorption / desorption sections 310, and configure the system so that some of the adsorption / desorption sections 310 adsorb carbon dioxide and the like, and in parallel with this, the other adsorption / desorption sections 310 desorb carbon dioxide. With this configuration, exhaust gas can be purified efficiently.

[0087] In addition, in the above embodiment, an example in which four adsorption / desorption units 310 are used has been shown, but the present invention is not limited to this, and the number of adsorption / desorption units 310 can be changed as desired. For example, it is also possible to configure the exhaust gas purification system 4 using a single adsorption / desorption unit 310.

[0088] Furthermore, the first temperature T1, the second temperature T2, and the third temperature T3 described in the above embodiment are not particularly limited, and can be changed appropriately depending on the processing contents.

[0089] In the above embodiment, the cooling section 320 includes the first cooling section 321, the second cooling section 322, the third cooling section 323, the fourth cooling section 324, and the fifth cooling section 325. However, the present invention is not limited to this, and the configuration of the cooling section 320 can be changed as desired. For example, if the exhaust gas can be sufficiently cooled by the first cooling section 321, it is also possible to adopt a configuration in which the fourth cooling section 324 that cools the exhaust gas downstream of the first cooling section 321 is not provided.

[0090] In the above embodiment, the path of the third cooling section 323 for cooling the desorbed carbon dioxide is partially shared with the first cooling section 321, and a common refrigerant is used for the first cooling section 321 and the third cooling section 323. However, the present invention is not limited to this. For example, the path of the third cooling section 323 may be partially shared with the path of the second cooling section 322 instead of the first cooling section 321, or may be configured independently from the other cooling sections (the first cooling section 321 and the second cooling section 322, etc.). Similarly, the path of the fourth cooling section 324 does not necessarily have to be partially shared with the second cooling section 322.

[0091] In the above embodiment, the exhaust gas that has passed through the adsorption / desorption section 310B is used to cool (pre-cool) the adsorption / desorption section 310D, but the present invention is not limited to this, and it is sufficient that the exhaust gas that has passed through one adsorption / desorption section 310 is used to adjust the temperature of the other adsorption / desorption section 310. For example, it is also possible to use the exhaust gas to heat the other adsorption / desorption section 310 instead of cooling it.

[0092] In the above embodiment, the two adsorption / desorption units 310 (the adsorption / desorption unit 310A and the adsorption / desorption unit 310C) to be heated are connected in series by the circulation path L21, but the present invention is not limited to this. That is, the adsorption / desorption unit 310A and the adsorption / desorption unit 310C can also be connected in parallel using a branched path.

[0093] In the above embodiment, the two adsorption / desorption units 310 (the adsorption / desorption unit 310B and the adsorption / desorption unit 310D) to be cooled are connected in parallel by the branched circulation path L21, but the present invention is not limited to this. That is, as shown in Fig. 2, the adsorption / desorption unit 310B and the adsorption / desorption unit 310D can also be connected in series using a path that does not branch.

[0094] In this way, the multiple adsorption / desorption units 310 can be connected in series or in parallel. Also, a configuration in which the series and parallel connections can be arbitrarily switched using a switching mechanism (switching valve, etc.) capable of switching the flow path of the refrigerant may be used. The series and parallel connections can be switched, for example, according to the required cooling capacity. Also, for example, when the multiple adsorption / desorption units 310 are connected in series, the pump capacity required to send the same volume of refrigerant to the adsorption / desorption units 310 can be made smaller than when the multiple adsorption / desorption units 310 are connected in parallel, so that power consumption can be reduced. Also, accordingly, the pump and paths (piping, etc.) can be made smaller and simpler, and space can be saved. [Explanation of symbols]

[0095] 4. Exhaust Gas Purification System 210 Adsorption / desorption part 211 Injection device 220 Cooling section 221 First cooling section 221b Radiator 222 Second cooling section 222a Radiator 223 Third cooling section 224 Fourth cooling section 225 Fifth cooling section L12 Pathway

Claims

1. an adsorption section capable of adsorbing carbon dioxide and nitrogen oxides contained in exhaust gas; a first cooling section that cools at least one of the exhaust gas guided to the adsorption section, the adsorption section, or the carbon dioxide desorbed from the adsorption section using a liquid-phase refrigerant; a second cooling section that cools at least one of the exhaust gas guided to the adsorption section, the adsorption section, or the carbon dioxide desorbed from the adsorption section, using a liquid-phase refrigerant that flows through a path independent of the first cooling section; An exhaust gas purification system comprising:

2. At least one of the first cooling section and the second cooling section is The cooling system includes a radiator that dissipates heat from the refrigerant. The exhaust gas purification system according to claim 1 .

3. The cooling system further includes an auxiliary cooling unit capable of cooling a refrigerant used in at least one of the first cooling unit or the second cooling unit using a refrigerant that undergoes a phase change. The exhaust gas purification system according to claim 1 .

4. The first cooling unit is Cooling the exhaust gas guided to the adsorption section, The second cooling section is The exhaust gas cooled by the first cooling section is cooled. The exhaust gas purification system according to claim 1 .

5. The first cooling unit is The exhaust gas guided to the adsorption section is cooled, and the adsorption section is heated using waste heat of the exhaust gas. The second cooling section is The adsorption unit is cooled. The exhaust gas purification system according to claim 1 .

6. The present invention further comprises a reduction unit capable of reducing nitrogen oxides in the adsorption unit by using urea or a hydrocarbon as a reducing agent. The exhaust gas purification system according to claim 1 .

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