JP2019112948A - Exhaust emission control device - Google Patents

Abstract

To efficiently exchange exhaust heat with a heat storage material and suppress leakage of the heat storage material.SOLUTION: An exhaust emission control device 12 includes: a catalyst carrier 16 provided inside of an exhaust pipe 14, formed into a honeycomb shape through which exhaust gas passes and carrying a catalyst for cleaning the exhaust gas; and a heat storage material gathering body 24 provided inside of the exhaust pipe 14 where a heat storage material container filled with a heat storage material is gathered into a honeycomb shape through which the exhaust gas passes.SELECTED DRAWING: Figure 1

Description

  The present application relates to an exhaust purification system.

  Patent Document 1 describes a heat storage material formed as a honeycomb structure having a plurality of cells which are separated by a ceramic partition and axially penetrated from one end face to the other end face and through which a fluid flows. .

  Patent Document 2 describes a main body of a heat storage material having a honeycomb structure, in which a fluid flow path through which a fluid flows and a heat storage medium portion in which a medium for storing the heat is contained. The heat storage medium portion is formed by sealing both end surfaces of the honeycomb.

JP 2012-255105 A Unexamined-Japanese-Patent No. 2011-52919

  In the technology described in Patent Document 1, the partition wall is arranged such that a plurality of cells communicating between two end surfaces (inlet end surface, outlet end surface) are formed, and the inside of the partition is filled with a latent heat storage material. It is done. As described above, in the structure in which the partition wall is filled with the latent heat storage material, since the partition wall is substantially impregnated with the latent heat storage material, the latent heat storage material may leak.

  In the technology described in Patent Document 2, the heat storage medium is provided in the plugged cells of the honeycomb structure, and the heat storage medium exchanges heat with the exhaust through the partition walls of the honeycomb structure, so that the heat exchange efficiency is improved. bad.

  Thus, the techniques described in any of the patent documents have room for improvement in terms of efficiently exchanging heat of exhaust heat with the heat storage material and suppressing leakage of the heat storage material.

  It is an object of the present invention to efficiently exchange heat of exhaust heat with a heat storage material and to suppress leakage of the heat storage material.

  In the first aspect, an exhaust pipe through which exhaust gas flows, a catalyst carrier that is provided inside of the exhaust pipe and is in a honeycomb shape through which the exhaust gas passes to carry a catalyst that purifies the exhaust gas; A heat storage material container provided inside and having a heat storage material enclosed therein has a heat storage material aggregated body collected in a honeycomb shape through which the exhaust gas passes.

  In this exhaust purification system, the exhaust gas flowing through the exhaust pipe can be purified by the catalyst carried by the catalyst carrier. Since the catalyst carrier is in a honeycomb shape through which the exhaust gas passes, the exhaust gas in the exhaust pipe smoothly passes through the catalyst carrier.

  Inside the exhaust pipe, a heat storage material aggregate is provided. Since the heat storage material container of the heat storage material aggregate is collected in a honeycomb shape through which the exhaust gas passes, the exhaust gas in the exhaust pipe smoothly passes through the heat storage material aggregate. Since the heat storage material is enclosed in the heat storage material container, leakage of the heat storage material is suppressed. Then, since the exhaust gas passes through the heat storage material aggregate, heat can be efficiently exchanged between the exhaust gas and the heat storage material.

  In a second aspect, in the first aspect, each of the plurality of exhaust flow paths in the catalyst carrier is any one of the plurality of exhaust flow paths in the heat storage material aggregate as viewed in the flow direction of the exhaust It is a shape that fits.

  Therefore, it is possible to suppress an increase in the resistance (pressure loss) to the flow of the exhaust gas due to the presence of the heat storage material sintered body.

  In the third aspect, in the first or second aspect, the catalyst support and the heat storage material aggregate are in contact in the flow direction of the exhaust gas.

  Thereby, the heat of the heat storage material aggregate can be transferred directly to the catalyst support, and the heat transfer efficiency is high as compared with the structure in which the heat storage material aggregate is separated from the catalyst support.

  In a fourth aspect, in any one of the first to third aspects, the catalyst is also supported on the outside of the heat storage material container in which it is concentrated.

  Not only the catalyst supported on the catalyst support but also the catalyst supported on the outside of the heat storage material container can purify the exhaust gas.

  In the fifth aspect, the exhaust gas passes through the exhaust pipe through which the exhaust gas flows, and the heat storage material container provided inside the exhaust pipe and having the heat storage material sealed therein and the catalyst for purifying the exhaust gas supported on the outer side thereof passes through the exhaust gas. And a heat storage material aggregate collected in a honeycomb shape.

  In this exhaust gas purification apparatus, a heat storage material aggregate is provided inside the exhaust pipe. Since the heat storage material container is collected in a honeycomb shape through which the exhaust gas passes, the exhaust gas in the exhaust pipe smoothly passes through the heat storage material aggregate. Then, since the exhaust gas passes through the heat storage material aggregate, heat can be efficiently exchanged between the exhaust gas and the heat storage material.

  Since a catalyst is supported on the outside of the heat storage material container, the exhaust gas can be purified by this catalyst.

  Since the heat storage material is enclosed in the heat storage material container, leakage of the heat storage material is suppressed. And since the heat storage material and the catalyst are at a position close to the inside and the outside of the heat storage material container, the heat of the heat storage material is efficiently transmitted to the catalyst as compared with the structure in which the heat storage material and the catalyst are separated. be able to.

  In a sixth aspect, according to any one of the first to fifth aspects, the heat storage material aggregate is a heat storage material sintered body in which a plurality of heat storage material containers are sintered.

  The heat storage material sintered body can sinter a plurality of heat storage material containers and maintain the shape in one point. Since a plurality of heat storage material containers are sintered, and an adhesive or the like for collecting the heat storage material containers is unnecessary, a wide surface area of the heat storage material container can be secured. As a result, it becomes possible to support many catalysts on the surface of the heat storage material container or to efficiently transfer heat between the inside and the outside of the heat storage material container.

  In a seventh aspect, in any one of the first to sixth aspects, the heat storage material container is made of ceramic.

  Since the heat storage material container is made of ceramic, for example, as compared with the configuration made of metal, it is easy to maintain high resistance to exhaust gas.

  In an eighth aspect according to any one of the first to seventh aspects, the heat storage material is a latent heat storage material having a melting point equal to or higher than the activation temperature of the catalyst.

  That is, the temperature when the heat storage material changes in phase from the liquid phase to the solid phase is equal to or higher than the activation temperature of the catalyst. The heat of solidification of the heat storage material makes it easy to maintain the catalyst at or above the activation temperature, and it is possible to efficiently purify the exhaust gas by the catalyst.

  The heat of the exhaust is efficiently exchanged with the heat storage material, and the leakage of the heat storage material can be suppressed.

FIG. 1 is a cross-sectional view showing the exhaust purification system of the first embodiment in a cross section along the longitudinal direction of the exhaust pipe. FIG. 2 is a perspective view showing a catalyst carrier of the exhaust purification system of the first embodiment. FIG. 3 is a front view showing a catalyst carrier of the exhaust purification system of the first embodiment in a partially enlarged manner. FIG. 4 is a front view showing, in an enlarged manner, an example different from FIG. 3 of the catalyst carrier of the exhaust purification system of the first embodiment. FIG. 5 is a front view showing, in an enlarged manner, an example different from FIGS. 3 and 4 of the catalyst carrier of the exhaust purification system of the first embodiment. FIG. 6 is a perspective view showing a heat storage material sintered body of the exhaust purification system of the first embodiment. FIG. 7 is a front view showing the heat storage material sintered body of the exhaust purification system of the first embodiment in a partially enlarged manner. FIG. 8 is a front view showing the heat storage material sintered body of the exhaust purification system of the first embodiment in a further enlarged manner than FIG. FIG. 9 is a partially broken perspective view showing the heat storage material container of the exhaust gas purification apparatus of the first embodiment. FIG. 10 is a cross-sectional view showing the exhaust purification system of the second embodiment in a cross section along the longitudinal direction of the exhaust pipe. FIG. 11 is a partially broken perspective view showing an example different from FIG. 9 of the heat storage material container applicable to the exhaust purification system of the first embodiment. FIG. 12 is an explanatory view showing the relationship between the gap of the catalyst carrier and the gap of the heat storage material sintered body in the exhaust purification system of the first embodiment. FIG. 13 is an explanatory view showing a first modified example different from FIG. 12 of the relationship between the gap of the catalyst carrier and the gap of the heat storage material sintered body in the exhaust purification system of the first embodiment. FIG. 14 is an explanatory view showing a second modified example different from FIGS. 12 and 13 of the relationship between the gap of the catalyst carrier and the gap of the heat storage material sintered body in the exhaust purification system of the first embodiment.

  Hereinafter, the exhaust purification system 12 of the first embodiment will be described with reference to the drawings.

  The exhaust purification device 12 is applied to an automobile having an engine, as an example. In the first embodiment, as shown in FIG. 1, the exhaust gas purification device 12 has a catalyst carrier 16 attached to the inside of the exhaust pipe 14 of the automobile. The catalyst support 16 is made of, for example, ceramic or metal.

  In the example shown in FIG. 1, the exhaust pipe 14 is substantially cylindrical, but a part in the longitudinal direction is a large diameter pipe 14B whose diameter is larger than that of the other part. The catalyst carrier 16 is disposed in the large diameter pipe 14B.

  Hereinafter, when simply referred to as “upstream side” and “downstream side”, the upstream side and the downstream side in the flow direction (the direction of the arrow F1) of the exhaust in the exhaust pipe 14 are respectively referred to.

  In the first embodiment, as shown also in FIG. 2 and FIG. 3, the catalyst support 16 has a cylindrical shape in contact with the inner peripheral surface of the large diameter pipe 14 B, and the inside is a honeycomb member. In the “honeycomb shape”, the exhaust flow path in the catalyst carrier 16 is divided into a plurality of parts as viewed in the flow direction of the exhaust (the direction of the arrow F1) by the plurality of walls 20 extending in the flow direction of the exhaust. It is a shape. In particular, in the present embodiment, the exhaust flow path (gap GP) having a predetermined shape as viewed in the flow direction of the exhaust is patterned and aligned. Therefore, the exhaust can pass through the gap GP occurring between the walls 20, and flows along the wall 20 as the exhaust passes through the gap GP in this way. That is, in the range where the honeycomb catalyst support 16 exists, the area of the member in contact with the exhaust gas is increased.

  The catalyst carrier 16 carries a catalyst 18 (see FIG. 3) for purifying the exhaust gas discharged from the engine.

  The shape of the wall when viewed in the flow direction of the exhaust may be, for example, a quadrangular shape (grid shape) as shown in FIG. 3, a hexagonal shape (honeycomb shape in a narrow sense) shown in FIG. It may be triangular as shown in FIG. Since the catalyst support 16 secures a wide surface area by being in the form of these various honeycombs, the amount of the catalyst 18 that can be supported on the surface is also large. Then, when the exhaust gas passes through the gap GP of the catalyst carrier 16, the exhaust gas can be brought into contact with the catalyst 18 that is carried in such a large amount, and the exhaust gas can be efficiently purified. In FIGS. 4 and 5, hatching of the wall 20 and the catalyst 18 are omitted.

  As shown in FIG. 1, the heat storage material sintered body 24 is disposed on the upstream side of the portion where the catalyst support 16 is disposed in the large diameter piping 14B. In the example shown in FIG. 1, the heat storage material sintered body 24 is in contact with the catalyst support 16 in the flow direction of the exhaust gas.

  As shown in FIG. 8, the heat storage material sintered body 24 is a member having an integral shape by sintering a plurality of heat storage material containers 34 and is an example of a heat storage material aggregate.

  As shown in FIG. 9, the heat storage material container 34 is a container in which the heat storage material 36 is enclosed. In the example shown in FIG. 9, the heat storage material container 34 has a spherical outer shell 38, and the outer diameter of the outer shell 38 is, for example, about 1 to 10 μm. The material of the outer shell 38 of the heat storage material container 34 may be, for example, a metal, but is a ceramic in the present embodiment. The heat storage material 36 is enclosed inside the outer shell 38. The heat storage material 36 can store this heat by receiving the heat from the high temperature exhaust gas, and can release the stored heat to the low temperature environment. A plurality of catalysts 18 are also carried on the outside of the outer shell 38 of the heat storage material container 34.

  The heat storage material sintered body 24 is formed by integrating a plurality of heat storage material containers 34 by sintering. The heat storage material sintered body 24 as a whole has a honeycomb shape like the catalyst support 16 as shown in FIG. 7, and has a plurality of wall bodies 40. Therefore, the exhaust gas can pass through the gap GQ of the wall 40 of the heat storage material sintered body 24. The gap GQ is an exhaust flow path in the heat storage material sintered body 24 when viewed in the flow direction of the exhaust gas (the arrow F1 direction).

  In the present embodiment, the shape of the honeycomb-shaped heat storage material sintered body 24 in the flow direction of the exhaust is the same as the shape of the catalyst carrier 16 in the flow direction of the exhaust. That is, as shown also in FIG. 12 in the present embodiment, the gap GQ which is an exhaust flow passage in the heat storage material sintered body 24 has the same shape (square shape) as the gap GP which is an exhaust flow passage in the catalyst carrier 16 is there. The plurality of gaps GQ and the plurality of gaps GP correspond to each other on a one-to-one basis, and the centers of the corresponding gaps GQ and GP coincide with each other. Therefore, the gap GQ and the gap GP are continuous in the same shape when viewed in the flow direction of the exhaust gas. In other words, the area occupied by the catalyst carrier 16 (the area where the exhaust gas can not pass) when viewed in the flow direction of the exhaust is the same as the area occupied by the heat storage material sintered body 24. Therefore, the resistance (pressure loss) to the flow of the exhaust gas does not increase due to the presence of the heat storage material sintered body 24.

  As described above, in order to suppress the increase in the resistance to the flow of the exhaust gas due to the presence of the heat storage material sintered body 24 as described above, the shape of the gap GQ viewed in the flow direction of the exhaust gas is the gap GP It does not have to completely match the shape of the. That is, even if the shape of the gap GQ viewed in the flow direction of the exhaust is larger than the shape of the gap GP, the presence of the heat storage material sintered body 24 increases the resistance to the flow of the exhaust, for example, as shown in FIG. This can be realized by the structure shown in FIG. In the first modified example shown in FIG. 13, when viewed in the flow direction of the exhaust, the gap GQ is a rectangle whose vertical side is about twice as long as the example shown in FIG. 12. Then, two gaps GP are accommodated in one gap GQ. Further, in the second modified example shown in FIG. 14, when viewed in the flow direction of the exhaust gas, the gap GQ is a square whose vertical and horizontal sides are about twice as long as the example shown in FIG. 12. Then, four gaps GP are accommodated in one gap GQ. As described above, when each of the plurality of gaps GP is shaped to fit (do not extend) in any of the plurality of gaps GQ, a portion of the heat storage material sintered body 24 is the gap GP in the flow direction of the exhaust gas. Since there is no clogging, it is possible to suppress an increase in pressure loss due to the heat storage material sintered body 24. 12 to 14 show the range in which the gaps GP appear in a 4 × 4 matrix, the catalyst carrier 16 is actually shaped so as to have more gaps GP.

  Even when the shape of the catalyst carrier 16 seen in the flow direction of the exhaust gas is the shape shown in FIG. 4 and FIG. 5, the heat storage material sintered body 24 has a flow of exhaust gas due to the presence of the heat storage material sintered body 24. The shape is designed to suppress the rise in resistance of the That is, the shape of the heat storage material sintered body 24 is such that each of the plurality of gaps GP of the catalyst carrier 16 fits (does not protrude) in any of the plurality of gaps GQ of the heat storage material sintered body 24. .

  The catalyst support 16 and the heat storage material sintered body 24 both have a honeycomb shape, so the catalyst support 16 and the heat storage material sintered body 24 constitute a honeycomb structure 42 inside the exhaust pipe 14. Structure. Further, in the first embodiment, in the honeycomb structure portion 42, the heat storage material sintered body 24 is from the upstream end 42A to the intermediate part 42C, and the catalyst carrier 16 is from the intermediate part 42C to the downstream end 42B. It is.

  Next, the operation of the present embodiment will be described.

  As shown in FIG. 1, the exhaust gas flowing in the exhaust pipe 14 passes through the heat storage material sintered body 24. Since the heat storage material 36 is enclosed in the plurality of heat storage material containers 34 of the heat storage material sintered body 24 as shown in FIG. 9, the exhaust can exchange heat with these heat storage materials 36. For example, if the temperature of the exhaust is higher than the temperature of the heat storage material 36, heat is transferred from the exhaust to the heat storage material 36. Conversely, if the temperature of the exhaust is lower than the temperature of the heat storage material 36, the heat storage material 36 Heat is transferred from the air to the exhaust.

  As shown in FIG. 7, the heat storage material sintered body 24 is formed in a honeycomb shape by sintering the heat storage material container 34. Therefore, the exhaust gas in the exhaust pipe 14 smoothly passes through the gap GQ of the heat storage material sintered body 24.

  Then, since the exhaust gas passes through the heat storage material sintered body 24 smoothly, heat can be efficiently exchanged between the exhaust gas and the heat storage material 36.

  In addition, the heat storage material 36 is enclosed in the heat storage material container 34 as shown in FIG. Therefore, the leakage of the heat storage material 36 is suppressed. Since the heat storage material 36 does not directly contact the exhaust, it does not react with the exhaust.

  In the exhaust pipe 14, the exhaust further passes through the catalyst carrier 16. Exhaust gas can be purified by the catalyst 18 supported by the catalyst support 16. Since the catalyst support 16 also has a honeycomb shape similar to the heat storage material sintered body 24, the exhaust gas smoothly passes through the gap GP (see FIG. 3) of the catalyst support 16. For example, even when the engine speed and generated torque are high and the pressure of the exhaust is high, the exhaust can be smoothly flowed in the exhaust pipe 14. In other words, even under conditions where high torque and high rotation are required and the flow rate of exhaust flowing through the exhaust pipe 14 increases, the pressure loss to the exhaust is reduced to give to the output torque and rotational speed of the engine. It is possible to reduce the impact.

  As described above, in the present embodiment, when high temperature exhaust flows through the exhaust pipe 14, the heat of the exhaust can be efficiently stored in the heat storage material 36.

  Then, in a state where heat is accumulated in the heat storage material 36, for example, when the engine is stopped, the exhaust gas does not flow in the exhaust pipe 14. In this case, the heat stored in the heat storage material 36 acts on the catalyst 18 of the catalyst support 16 to suppress the temperature decrease of the catalyst 18. The temperature of the catalyst 18 can be maintained high for a long time, for example, above the activation temperature, as compared with the exhaust gas purification device having a structure without the heat storage material 36. The “activation temperature” is the lower limit temperature at which the catalyst 18 exerts the effect of purifying the exhaust gas highly.

  Then, for example, even when the engine which has been stopped is restarted and low temperature exhaust flows through the exhaust pipe 14, if the temperature of the catalyst 18 of the catalyst carrier 16 is maintained high, the effect of purifying exhaust by the catalyst 18 Can be demonstrated high.

  Furthermore, when a catalytic reaction with the catalyst 18 occurs in the heat storage material sintered body 24, it is possible to raise the temperature of the passing exhaust gas by this catalytic reaction. Then, by causing the temperature rise exhaust heat to act on the catalyst 18 of the catalyst support 16, it is possible to suppress the temperature drop of the catalyst 18 of the catalyst support 16 or shorten the temperature rise time. It is.

  In the present embodiment, the heat storage material sintered body 24 is in contact with the catalyst support 16 in the flow direction of the exhaust gas. Therefore, the heat of the heat storage material sintered body 24 can be directly transmitted to the catalyst 18 of the catalyst support 16, and the heat storage material sintered body 24 is separated from the catalyst support 16 (non-contact) Heat transfer efficiency is high compared to.

  As described above, in the present embodiment, when the high temperature exhaust gas flows through the exhaust pipe 14, the heat of the exhaust gas can be efficiently applied to the heat storage material 36 to be stored. Then, by causing the heat stored in the heat storage material 36 to act on the catalyst of the catalyst carrier 16, the effect of the catalyst purifying the exhaust can be maintained high.

  Further, in the present embodiment, the catalyst support 16 and the heat storage material sintered body 24 are both in a honeycomb shape, and the shape viewed in the flow direction of the exhaust is the catalyst support 16 and the heat storage material sintered body 24 Is the same. Therefore, the presence of the heat storage material sintered body 24 suppresses the increase in the resistance (pressure loss) to the flow of the exhaust, and the smooth flow of the exhaust is realized.

  Next, a second embodiment will be described. In the second embodiment, the same elements, members, and the like as those in the first embodiment are denoted by the same reference numerals, and detailed descriptions thereof will be omitted.

  As shown in FIG. 10, the exhaust gas control apparatus 52 of the second embodiment also has a honeycomb-shaped heat storage material sintered body 24. In the second embodiment, the heat storage material sintered body 24 is provided in the honeycomb structure portion 42 from the upstream end 42A to the downstream end 42B. That is, the whole of the honeycomb structure portion 42 is configured by the heat storage material sintered body 24.

  In the exhaust gas purification apparatus 52 of the second embodiment configured as described above, the exhaust gas flowing in the exhaust pipe 14 passes through the heat storage material sintered body 24, and the heat storage material 36 enclosed in a plurality of heat storage material containers 34. Heat exchange is possible.

  Since the heat storage material sintered body 24 is formed in a honeycomb shape by sintering the heat storage material container 34, the exhaust gas passes smoothly, and the heat can be efficiently exchanged between the exhaust gas and the heat storage material 36. Since the heat storage material 36 is enclosed in the heat storage material container 34, leakage of the heat storage material 36 is suppressed.

  In the second embodiment, the heat storage material container 34 carrying the catalyst 18 is disposed on the entire honeycomb structure 42 (from the upstream end 42A to the downstream end 42B). The catalyst 18 can purify the exhaust gas.

  The heat storage material 36 can receive heat from the exhaust and can store heat, so that the heat acts on the catalyst 18 to suppress the temperature decrease of the catalyst 18. For example, the temperature of the catalyst 18 is maintained over the activation temperature for a long time it can. Even if low temperature exhaust flows through the exhaust pipe 14 at the time of engine restart, if the temperature of the catalyst 18 of the heat storage material container 34 is maintained high, the effect of purifying the exhaust can be exhibited highly.

  When the exhaust gas reacts with the catalyst 18 on the upstream side of the heat storage material sintered body 24, reaction heat is generated. The exhaust gas whose temperature has been raised by the reaction heat also has an effect of being able to suppress the temperature decrease of the catalyst 18 on the downstream side of the heat storage material sintered body 24.

  In the first embodiment, it is also possible to use the heat storage material container 54 of the modified example shown in FIG. The heat storage material container 54 has a structure in which the catalyst 18 is not supported on the outside of the outer shell 38. Even in a structure using a heat storage material sintered body obtained by sintering such a heat storage material container 54, exhaust gas can be purified by the catalyst 18 of the catalyst carrier 16 located on the downstream side. On the other hand, in the heat storage material sintered body 24 using the heat storage material container 34 shown in FIG. 9, the exhaust gas can be purified also by the catalyst 18 attached to the outside of the outer shell 38 of the heat storage material container 34.

  In each of the above embodiments, the material of the outer shell 38 of the heat storage material container 34 may be, for example, metal, but if made of ceramic, the catalyst 18 is supported on the ceramic fine structure (micro unevenness and holes) In addition, the dropping of the catalyst 18 from the shell 38 can be suppressed.

  Further, by making the outer shell 38 of ceramic, for example, it is possible to suppress the deterioration due to the contact of the exhaust as compared with the case of metal. And, by suppressing the deterioration of the outer shell 38, the heat storage material 36 can be kept sealed in the outer shell 38 for a long period of time.

  In the exhaust gas purification apparatus according to the embodiment described above, the heat storage material sintered body 24 in which the heat storage material container 34 is sintered is exemplified as the heat storage material aggregate. It is not limited to 24. For example, a plurality of heat storage material containers 34 may be a heat storage material aggregate in which the plurality of heat storage material containers 34 are bonded by an adhesive to have a predetermined shape. In the heat storage material sintered body 24 of each of the above embodiments, since a member such as an adhesive for fixing the heat storage material containers 34 to each other is unnecessary, efficient heat exchange between the exhaust gas and the heat storage material 36 is possible. is there.

  In the exhaust gas purification apparatus according to each of the above-described embodiments, the heat storage material 36 is not particularly limited as long as it can store heat by receiving heat from high temperature exhaust and can dissipate heat to low temperature exhaust. For example, a molten salt having a melting point in the range of 100 ° C. to 600 ° C. can be used. A molten salt is a substance obtained by melting a solid salt or oxide at room temperature into a liquid by heating, and is composed of a cation and an anion. And enthalpy changes with phase change (melting, first order transition, or second order transition), and heat storage and heat radiation are carried out.

  In each embodiment, the phase change of the heat storage material 36 at the time of actually storing and releasing heat may be melting accompanied by phase transition between the solid phase and the liquid phase, and at the time of phase change, the heat storage material stores heat and releases heat as latent heat. . On the other hand, heat may be stored and released as a phase change that does not involve a phase transition between the solid phase and the liquid phase.

  The temperature of the phase change of the heat storage material 36 is preferably a temperature higher than the activation temperature of the catalyst 18. As a result, the temperature at the phase transition of the heat storage material 36 becomes equal to or higher than the activation temperature of the catalyst 18, so it is easy to maintain the state where the catalyst 18 can efficiently purify the exhaust gas.

  Note that even in the temperature range where the heat storage material does not undergo phase transition, heat is accumulated and dissipated as sensible heat, so the heat accumulation and dissipation as the sensible heat may be used to suppress the temperature decrease of the catalyst 18.

  In the molten salt, particularly, the molten salt having a phase change temperature in the range of 100 ° C. or more and 600 ° C. or less can perform heat exchange with the exhaust efficiently and can be preferably applied to the exhaust purification system of each embodiment and modification. .

  Depending on the type of molten salt, there are also molten salts whose volume changes due to phase change. In the case of using a molten salt whose volume changes, in the heat storage material container 34, a sufficient volume may be secured inside the outer shell 38 so as to be able to absorb the volume change of the molten salt.

12 exhaust purification device 14 exhaust pipe 16 catalyst support 18 catalyst 24 heat storage material sintered body 34 heat storage material container 36 heat storage material 38 outer shell 42 honeycomb structure portion 42A upstream end portion 42B downstream end portion 42C intermediate portion 52 exhaust purification device 54 Heat storage material container

Claims (8)

An exhaust pipe through which the exhaust flows,
A catalyst carrier, which is provided inside the exhaust pipe, has a honeycomb shape through which the exhaust gas passes, and carries a catalyst for purifying the exhaust gas;
A heat storage material aggregate which is provided inside the exhaust pipe and in which a heat storage material container in which a heat storage material is enclosed is collected in a honeycomb shape through which the exhaust gas passes;
An exhaust purification device having the   The exhaust gas purification method according to claim 1, wherein each of the plurality of exhaust flow paths in the catalyst carrier has a shape that fits in any of the plurality of exhaust flow paths in the heat storage material aggregate when viewed in the flow direction of the exhaust. apparatus.   The exhaust gas purification apparatus according to claim 1 or 2, wherein the catalyst support and the heat storage material aggregate are in contact with each other in the flow direction of the exhaust gas.   The exhaust gas purification apparatus according to any one of claims 1 to 3, wherein the catalyst is also carried on the outside of the heat storage material container in which the catalyst is collected. An exhaust pipe through which the exhaust flows,
A heat storage material aggregate in which a heat storage material container provided inside the exhaust pipe and having a heat storage material enclosed therein and a catalyst supporting the exhaust gas purification carried thereon is collected in a honeycomb shape through which the exhaust gas passes;
An exhaust purification device having the   The exhaust gas purification apparatus according to any one of claims 1 to 5, wherein the heat storage material aggregate is a heat storage material sintered body in which a plurality of heat storage material containers are sintered.   The exhaust gas purification apparatus according to any one of claims 1 to 6, wherein the heat storage material container is made of ceramic.   The exhaust gas purification apparatus according to any one of claims 1 to 7, wherein the heat storage material is a latent heat storage material having a melting point equal to or higher than an activation temperature of the catalyst.