Patent ID: 12186717

REFERENCE SIGNS

10mixer assembly1—mixer11shell111installation areaS1first space12doser mounting base120first swirl structure121spray inlet122mounting plate123swirl base1230notch124spiral flow passage,125profile line coincident area126swirl blade component13swirl cone131air inlet opening132second swirl structure133swirl blade component2doser21spray end

DETAILED DESCRIPTION OF EMBODIMENTS

The following discloses a variety of different implementation manners or embodiments for implementing the described subject technical proposal. In order to simplify the disclosure, specific examples of the elements and arrangements are described below. Of course, these are only examples, not limiting the scope of protection of the present invention.

In addition, for example, “one embodiment”, “an embodiment”, and/or “some embodiments” refer to a feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that “an embodiment” or “one embodiment” or “one or more embodiments” mentioned twice or more in different positions in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures or characteristics in one or more embodiments of the present application may be appropriately combined.

As shown inFIGS.1to6, in some embodiments, the mixer assembly10may comprise a mixer1and a doser2. The mixer1comprises a shell11, which defines a first space S1. The first space S1receives engine exhaust. The shell11has a mounting area111formed on a wall of the shell11. The doser2is installed in the mounting area111to be installed to the mixer1to form the mixer assembly10. As shown inFIGS.1and2, the exhaust generated by engine operation may enter the first space S1from below the shell11.

The mixer1also comprises a doser mounting base12, which is arranged in the mounting area111for installing the doser2. Wherein, the doser mounting base12comprises a spray inlet121, as an inlet end for the spray that is sprayed by the doser2entering the first space S1. As shown inFIG.1, the spray end21of the doser2is located at the spray inlet121, so that the spray of the reductant solution sprayed by the doser2is released into the mixer1from the spray inlet121.

As shown inFIGS.2to7, the doser mounting base12also comprises a first swirl structure120surrounding the spray inlet121to the exhaust form a swirl around the spray inlet121, so that the spray that is sprayed by the doser2is fully contacted and mixed with the hot swirl exhaust immediately after entering the mixer from the spray inlet121. Therefore, the spray is fully decomposed from the beginning of the diffusion process inside the mixer1, or the position of the spray inlet121may be easy to gather droplets or liquid films to form urea, and swirling flow of the spray inlet121can purge and decompose it in time to reduce urea crystallization. Moreover, because the first swirl flow structure120is located nearby the spray inlet, as shown inFIGS.4to6for example, it is roughly tangent to the profile line of the spray inlet121, so that the airflow movement at the spray inlet121is a swirling movement, and the negative impact on the spray is very small, to make the spray be fully extended and diffused in the mixer along the given spray direction, ensuring sufficient mixing distance between the spray and the exhaust. Therefore, the urea can be fully decomposed, and fully and evenly mixed with the exhaust. The principle that urea crystallization can be reduced by adopting the above embodiment is that the inventor accidentally found in practice that, as shown inFIG.8, mixer1will have more urea crystals3around the spray inlet121. After adopting the first swirl structure, as shown inFIG.9, the urea crystals at the spray inlet121are almost eliminated, greatly improving the urea crystallization phenomenon inside mixer1, and making the mixer meet the requirements. The simulation results shown inFIG.7show that the swirling effect near the spray inlet121is very strong.

As shown inFIG.3andFIG.4, in an embodiment, the specific structure of the first swirl structure120and the doser mounting base12can be that the doser mounting base12comprises a mounting plate122for mounting in the mounting area111, the mounting plate122is provided with a spray inlet121, the doser mounting base12also comprises a swirl base123, and the swirl base123is fixed to the mounting plate122. The swirl base123is provided with a spiral flow passage124, which surrounds the spray inlet121and forms a first swirl structure120. As shown inFIG.4, the streamline of the spiral flow passage124is a spiral.

In an embodiment, as shown inFIG.4, the specific structure of the spiral flow passage124can be that the edge of the swirl base123has a notch1230, and the spiral flow passage124extends from the notch1230to the end of the spiral flow passage124and is tangent to the profile line of the spray inlet121, which can make the swirl effect around the spray inlet121better. The tangential structure is not limited to that shown in the figure. The profile line of the spiral flow passage124coincides with the profile line of the spray inlet121to form the profile coincident area125, which is tangent at the end of the profile coincident area125. Otherwise, it can be tangent to the profile line of the spray inlet121only at the end of the spiral flow passage124, and the rest is not coincident. It can be understood that the tangency here refers to roughly tangency rather than strictly tangency. The beneficial effect of the first swirl structure120as the spiral flow passage124is that the spiral flow passage124naturally forms a swirling motion, which flows smoothly and has a high flow efficiency of the exhaust flow, and the gas flow does not need additional loss of work to convert into other forms of energy.

In another embodiment, as shown inFIG.5, compared with the embodiment shown inFIG.4, the first swirl structure120comprises swirl blade component126in addition to the spiral flow passage124. The swirl blade component126can be located on the inner side of the spiral flow passage124, for example, installed on the inner wall of the spiral flow passage124as shown inFIG.5. At this time, the first swirl structure120comprises the spiral flow passage124and a swirl blade component126. That is, the combined action of the spiral streamline and the swirl blade component form swirling exhaust around the spray inlet121. In this way, the exhaust of the first swirl structure120can be strengthened, which is suitable for engines with large displacement. Because larger displacement engines need more urea solution spray, stronger swirl can more effectively prevent urea crystallization.

In another embodiment, the first swirl structure may also comprise a swirl blade component without a spiral flow passage. The specific position of the swirl blade component126can be directly arranged at the spray inlet121as shown inFIG.6, or it can be arranged on the inner wall of the swirl base123around the spray inlet121similar toFIG.5. In the structures shown inFIG.5andFIG.6, the first swirl structure120comprises both the spiral flow passage124and the swirl blade component126. It can be understood that in this another embodiment, the first swirl structure120does not comprise the spiral flow passage124, that is, the swirl base123is removed from the structure inFIG.6, or the swirl base123does not have a spiral flow passage in the structure inFIG.5. For example, the notch1230of the swirl base123is closed to form an annular swirl base123, and the swirl blade component126is located on the inner ring wall of the annular swirl base123. In this way, the effect of reducing urea crystallization can also be obtained.

As shown inFIGS.3to6, the swirl base123and the mounting plate122can be fixedly connected by welding, and such a connection structure is stable and reliable. Otherwise, the swirl base123and the mounting plate122can be an integral component, for example, integrated by the casting process, 3D printing process, etc., which can also make the structure of the swirl base and the mounting base stable and reliable.

Continuing to refer toFIGS.1to3, in some embodiments, the shell11of the mixer1is also provided with a swirl cone13. The small end of the swirl cone13is arranged corresponding to the spray inlet121. The side wall of the swirl cone13is provided with an air inlet opening131. The air inlet opening131is provided with a second swirl structure132. By arranging the structure of the swirl cone13, the spray beam of the spray can fully extend and diffuse. Besides, by arranging the air inlet opening with the swirl structure on the side wall, sufficient swirl exhaust can be ensured to be fully mixed with urea spray, so that urea is fully decomposed and evenly mixed, and the direct impact on the spray beam can also be reduced. The specific structure of the second swirl structure132can be that the side wall of the swirl cone13has a plurality of air inlet openings131distributed in the circumferential direction, and the second swirl structure132comprises at least one swirl blade component133arranged at the air inlet opening131. For example, each air inlet opening131shown in the figure of the embodiment should have a corresponding swirl blade component133, but not limited to that. For example, not every but only a part of the air inlet openings131may have a corresponding structure such as a swirl blade component, which has a good swirl effect and is easy to process.

According to the above description, referring toFIG.10, the mixing method of exhaust and urea spray described in the above embodiment comprises:making the spray of reductant solution enters the mixing chamber from the spray inlet of the mixing chamber.

For example, as shown inFIG.1, the spray of urea solution sprayed by the doser2enters the mixer1from the spray inlet121to mix with the exhaust.

At least part of the exhaust forms swirling exhaust at the spray inlet, and the swirling exhaust is mixed with the spray at the spray inlet.

As shown inFIGS.2to7, part of the exhaust passes through the swirling structure120, such as the spiral flow passage124and/or the swirl blade component126, and forms a swirling flow at the spray inlet. The swirling flow is mixed with the spray of urea solution at the spray inlet121to reduce urea crystallization.

In the above embodiments, a flowchart is used to illustrate the steps of mixing exhaust and urea spray according to the structure of some embodiments of the application. It should be understood that the preceding or following operations are not necessarily performed accurately in sequence. Technicians can also add other operations to these procedures or remove one or more operations from these procedures.

It can be seen from the above that the beneficial effect of adopting the mixer, mixer assembly and mixing method described in the above embodiment is that by arranging the first swirling structure around the spray inlet, the spray of the doser is fully mixed with the swirling exhaust immediately after entering the mixer, so that the spray is fully decomposed to reduce urea crystallization and improve the mixing effect of the mixer, and the service life of the mixer assembly and the exhaust system thereof are prolonged.

Although the above embodiments of the disclosure are disclosed as above, they are not intended to define the present invention. Any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any amendments, equivalent changes and modifications made to the above embodiments according to the technical essence of the disclosure without departing from the technical proposals of the disclosure fall within the scope of protection defined in the claims of the present invention.