Patent Application
20220097001
The present disclosure relates to a mixing member, an exhaust purification apparatus, and a vehicle.
In the related art, for an exhaust purification apparatus for an internal combustion engine, a configuration is known in which ammonia is generated by a reducing agent such as urea water and reduction action of the ammonia and nitrogen oxide in an exhaust gas is promoted using a selective reduction catalyst. For such a configuration, a configuration including a mixing member for mixing a reducing agent and an exhaust gas is known.
For example, Patent Literature (hereinafter, referred to as “PTL”) 1 discloses a configuration including: a reducing agent supply part disposed inclined with respect to an emission direction; and a mixing member disposed vertically with respect to a supply direction of a reducing agent of the reducing agent supply part. In this configuration, the mixing member directly receives the reducing agent supplied from the reducing agent supply part, thereby improving mixing efficiency of the reducing agent and an exhaust gas, and further improving purification efficiency of the exhaust gas.
In the configuration described in PTL 1, however, a gas flow path in the mixing member is parallel to the supply direction of the reducing agent so that there is a case where the reducing agent passes through the gas flow path as it is, without being mixed by the mixing member, to be deposited on a downstream side of the mixing member. For this reason, the configuration described in PTL 1 has certain limitations as a configuration of improving mixing efficiency of a reducing agent and an exhaust gas.
An object of the present disclosure is to provide a mixing member, an exhaust purification apparatus, and a vehicle that are capable of improving mixing efficiency of an reducing agent and an exhaust gas, and further improving purification efficiency of the exhaust gas.
A mixing member according to the present disclosure mixes a reducing agent and an exhaust gas in an exhaust pipe. The reducing agent is supplied in a supply direction inclined with respect to an emission direction in which the exhaust gas flows. The mixing member includes a main body part. The main body part includes: a gas inlet; a gas outlet;
and a gas flow path communicating the gas inlet with the gas outlet and causing the exhaust gas and the reducing agent to be mixed therein. The gas inlet is provided on an end surface of the main body part. The end surface is located on an upstream side in the emission direction when the mixing member is disposed in the exhaust pipe. The end surface is disposed inclined with respect to the emission direction so as to face an upstream side in the supply direction of the reducing agent. The gas flow path is inclined with respect to the supply direction and extends parallel to the emission direction.
An exhaust purification apparatus according to the present disclosure includes: the exhaust pipe; a selective reduction catalyst provided in the exhaust pipe and promoting reduction of nitrogen oxide in the exhaust gas; a reducing agent supply part provided in a stage before the selective reduction catalyst in the exhaust pipe and supplying the reducing agent in the supply direction; and the mixing member disposed to face the reducing agent supply part in the supply direction in the exhaust pipe.
A vehicle according to the present disclosure includes the exhaust purification apparatus described above.
Advantageous Effects of Invention
According to the present disclosure, it is possible to improve mixing efficiency of a reducing agent and an exhaust gas, and further to improve purification efficiency of the exhaust gas.
Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the accompanying drawings.
As illustrated in
An exhaust gas generated from internal combustion engine 1 flows through exhaust pipe 110. Exhaust pipe 110 is provided with reducing agent supply part 120, mixing member 140, selective reduction catalyst 130, and the like in this order from an upstream side of a direction in which an exhaust gas flows (a direction from the left to the right in the drawing; hereinafter, referred to as “emission direction”).
Reducing agent supply part 120 supplies a reducing agent (urea water) for generating ammonia to exhaust pipe 110. Further, reducing agent supply part 120 supplies the reducing agent in a direction inclined with respect to the emission direction (a right obliquely downward direction in the drawing; hereinafter, referred to as “supply direction”). When the reducing agent is supplied to exhaust pipe 110 by reducing agent supply part 120, the reducing agent is hydrolyzed due to the temperature in exhaust pipe 110 to generate ammonia.
Selective reduction catalyst 130 is provided in a stage after reducing agent supply part 120 in exhaust pipe 110, and adsorbs ammonia generated based on the reducing agent supplied by reducing agent supply part 120. Selective reduction catalyst 130 reacts the adsorbed ammonia with nitrogen oxide contained in an exhaust gas passing through selective reduction catalyst 130 to reduce the nitrogen oxide.
As illustrated in
As illustrated in
As illustrated in
Upstream end surface 141B extends so as to be orthogonal to supply direction A and is inclined with respect to emission direction B such that upstream end surface 141B faces an upstream side in supply direction A when mixing member 141 is disposed in exhaust pipe 110. By configuring upstream end surface 141B in this manner, main body part 141 is capable of directly receiving the reducing agent supplied from reducing agent supply part 120 on upstream end surface 141B.
Further, upstream end surface 141B and downstream end surface 141A described above are open, and main body part 141 is configured to pass through in emission direction B. Accordingly, an opening portion of upstream end surface 141B forms gas inlet C1 for an exhaust gas, and an opening portion of downstream end surface 141A forms gas outlet C2 for an exhaust gas. Mixing part 142 is provided in an internal space of main body part 141.
As illustrated in
As illustrated in
Heat reception part 143 protrudes from upstream end surface 141B of main body part 141 so as to intersect emission direction B. Specifically, heat reception part 143 protrudes from an upstream-side end part of flat plate member 142A forming a lower wall of gas flow path 142B, among flat plate members 142A forming gas flow paths 142B, so as to intersect emission direction B, and extends in a direction parallel to supply direction A.
Since configuring heat reception part 143 as such makes it easy for an exhaust gas moving towards mixing member 140 to collide with heat reception part 143, heat of the exhaust gas is easily transferred by heat reception part 143. As a result, mixing member 140 in its entirety is easily heated so that it is possible to improve mixing efficiency of the reducing agent, which has entered mixing member 140, and an exhaust gas.
Further, since heat reception part 143 extends in the direction parallel to supply direction A, the reducing agent of reducing agent supply part 120 easily enters mixing member 140 along heat reception part 143. As a result, mixing member 140 easily receives the reducing agent so that it is possible to improve mixing efficiency in mixing member 140, and further to improve purification efficiency in exhaust purification apparatus 100.
Further, a wall surface (flat plate member 142A) forming one of gas flow paths 142B in mixing member 140 intersects imaginary line X extending in supply direction A from supply port 120A for the reducing agent in reducing agent supply part 120.
Thus, mixing member 140 is capable of easily receiving the reducing agent supplied from reducing agent supply part 120. As a result, it is possible to restrain the reducing agent from passing through gas flow path 142B, without being mixed in mixing member 140, to be deposited on exhaust pipe 110 on a downstream side of mixing member 140.
Further, mixing member 140 is preferably disposed in region Z including intersection Y2 between imaginary line X, which extends in supply direction A from supply port 120A for the reducing agent in reducing agent supply part 120, and exhaust pipe 110.
By disposing mixing member 140 in this manner, mixing member 140 is capable of surely receiving the reducing agent supplied from reducing agent supply part 120. Thus, it is possible to restrain the reducing agent from passing through gas flow path 142B, without being mixed in mixing member 140, to be deposited on exhaust pipe 110 on the downstream side of mixing member 140.
As a result, the reducing agent can be surely received by mixing member 140 so that it is possible to improve mixing efficiency in mixing member 140, and further to improve exhaust efficiency in exhaust purification apparatus 100.
Note that, in the embodiment described above, downstream end surface 141A of mixing member 140 is orthogonal to emission direction B, but the present disclosure is not limited thereto. For example, as illustrated in
Further, in this configuration, downstream end surface 141A is inclined such that downstream end surface 141A is located more on an upstream side of emission direction B as downstream end surface 141A is upwardly directed. Accordingly, mixing member 140 is configured such that a member located on an upper side of mixing member 140 has a small length in emission direction B. Thus, it is possible to decrease the size of mixing member 140 so that decreases in the weight and cost can be achieved. Further, since the heat capacity of mixing member 140 can be decreased by decreasing the size of mixing member 140, it is possible to contribute to a heating effect by a relatively small amount of heat.
Further, in the embodiment described above, heat reception part 143 is disposed parallel to supply direction A, but the present disclosure is not limited thereto, and heat reception part 143 may not be disposed parallel to supply direction A.
Further, in the embodiment described above, upstream end surface 141B of mixing member 140 is orthogonal to supply direction A, but the present disclosure is not limited thereto. Upstream end surface 141B may not be orthogonal to supply direction A as long as upstream end surface 141B intersects supply direction A.
Further, in the embodiment described above, heat reception part 143 is provided in mixing member 140, but the present disclosure is not limited thereto, and heat reception part 143 may not be provided.
In addition, any of the embodiment described above is only illustration of an exemplary embodiment for implementing the present disclosure, and the technical scope of the present disclosure shall not be construed limitedly thereby. That is, the present disclosure can be implemented in various forms without departing from the gist or the main features thereof.
This application is based upon Japanese Patent Application No. 2018-223380, filed on Nov. 29, 2018, the entire contents of which are incorporated herein by reference.
The mixing member of the present disclosure is useful as a mixing member, an exhaust purification apparatus, and a vehicle that are capable of improving mixing efficiency of a reducing agent and an exhaust gas, and further improving purification efficiency of the exhaust gas.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2018-223380 | Nov 2018 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2019/045792 | 11/22/2019 | WO | 00 |
