CN218407577U - Mixer, exhaust system and internal combustion engine equipment thereof - Google Patents

Abstract

The application relates to a mixer, an exhaust system and an internal combustion engine apparatus. Wherein the mixer comprises a mixing assembly (11), the mixing assembly (11) comprising: a first swirl section (111) having an inlet opening (1110), the inlet opening (1110) for providing an inlet for exhaust gas into a mixing space (S) of the mixer (1); a first mixing section (121) downstream of the first swirl section (111) and fluidly connected adjacent to the first swirl section (111); a second swirl section (112) downstream of the first mixing section (121) and fluidly connected adjacent to the first mixing section (121), the second swirl section (112) being in the same or opposite swirl direction as the first swirl section (111); and a second mixing section (122) downstream of the second cyclonic section (112) and fluidly connected adjacent to the second cyclonic section (112).

Description

Mixer, exhaust system and internal combustion engine equipment thereof

Technical Field

The application relates to a mixer, an exhaust system and an internal combustion engine arrangement thereof.

Background

The exhaust system treats hot exhaust gases produced by the internal combustion engine through various upstream exhaust components to reduce exhaust pollutants. The various upstream exhaust components may include one or more of the following: pipes, filters, valves, catalysts, mufflers, etc. For example, an upstream exhaust component directs exhaust gases into a Diesel Oxidation Catalyst (DOC) having an inlet and an outlet. Downstream of the Diesel oxidation catalyst, a Diesel Particulate Filter (DPF) may be arranged. Downstream of the diesel oxidation catalyst and the optional diesel particulate filter is a Selective Catalytic Reduction (SCR) reactor having an inlet and an outlet. The outlet passes exhaust gas to a downstream exhaust component. A mixer (mixer) is positioned downstream of the outlet of the DOC or DPF, upstream of the inlet of the SCR. Within the mixer, the exhaust gas produces a swirling or rotational motion. An injector (injector) is used to inject a reductant, such as an aqueous urea solution, into the exhaust stream from upstream of the SCR so that the mixer can sufficiently mix the urea and exhaust gases together for discharge into the SCR for reduction reactions to produce nitrogen and water to reduce the nitrogen oxide emissions of the engine. However, there are still improvements in the existing mixers, such as further improvement in the uniformity of mixing of exhaust gas with urea, reduction in urea crystallization, and the like.

Therefore, there is a need in the art for a mixer with good mixing uniformity and low urea crystallization rate, and an exhaust system and an internal combustion engine apparatus with low nitrogen oxide emissions.

SUMMERY OF THE UTILITY MODEL

It is an object of the present invention to provide a mixer for an exhaust system.

It is another object of the present invention to provide an exhaust system.

It is a further object of the present invention to provide an internal combustion engine apparatus.

According to an aspect of the present invention, a mixer for an exhaust system, the mixer includes a mixing assembly, the mixing assembly includes: a first swirl section having an inlet opening for providing an inlet for exhaust gas into a mixing space of the mixer; a first mixing section downstream of the first cyclonic section and fluidly connected adjacent to the first cyclonic section; a second swirl section downstream of and fluidly connected adjacent to the first mixing section, the second swirl section having a swirl direction the same as or opposite to that of the first swirl section; and a second mixing section downstream of and fluidly connected adjacent to the second cyclonic section.

In one or more embodiments of the mixer, the first swirl section includes a swirl cone, a side wall of the swirl cone has a plurality of the air inlet openings, a plurality of the air inlet openings are distributed along a circumferential direction of the swirl cone, a small end port of the swirl cone is a spray opening for providing an inlet for a reducing agent spray to enter a mixing space of the mixer, and a large end port of the swirl cone is fluidly connected adjacent to an upstream end of the first mixing section.

In one or more embodiments of the mixer, the air inlet opening is provided with a first swirl vane.

In one or more embodiments of the mixer, the first mixing section comprises a first straight pipe section, an upstream end of the first straight pipe section is connected with a downstream end of the first cyclone section, and a downstream end of the first straight pipe section is connected with the second cyclone section.

In one or more embodiments of the mixer, the first mixing section further includes a second straight pipe section, the second straight pipe section is sleeved on the first straight pipe section at a position radially outside the first straight pipe section, and a radial gap between the first straight pipe section and the second straight pipe section provides an exhaust bypass channel.

In one or more embodiments of the mixer, the second straight tube section extends downstream to a third straight tube section providing space for the second swirl section and/or second mixing section.

In one or more embodiments of the mixer, the second swirl section includes a tube section and a swirl assembly located within the tube section, the swirl assembly including a plurality of second swirl vanes radiating outwardly from a center of the tube section.

In one or more embodiments of the mixer, the second swirl vane comprises a body portion and a connecting portion; the connecting parts comprise a first connecting part and a second connecting part which are respectively positioned at the two radial ends of the blade body part, and the connecting parts extend in the circumferential direction and are fixedly connected with the pipe section; the body part comprises a first body part and a second body part which extend from a central part to two radial ends respectively, the first body part and the second body part are provided with swirl surfaces, the central part is provided with a slot, and each second swirl blade is connected by inserting the central part.

In one or more embodiments of the mixer, the third straight tube section comprises the tube section, and the connection of the second swirl vanes is connected with the tube section by a plug weld structure.

In one or more embodiments of the mixer, the mixer further comprises an outer cover defining a flow space of the mixer with the base, the mixing assembly being located in the flow space F, the base having an inlet portion and an outlet portion of the mixer.

In one or more embodiments of the mixer, the outer cover has an injector mounting hole in communication with the first swirl section, the first swirl section having an inlet end of the mixing assembly in communication with an inlet portion of the mixer, and the second mixing section having an outlet end of the mixing assembly in communication with an outlet portion of the mixer.

In one or more embodiments of the mixer, the mixer further has a partition separating the inlet and outlet of the mixer, and the mixing assembly is supported by the partition, and the first swirl section has an end port that is an injection opening for providing an inlet for a spray of reductant into the mixing space of the mixer, the end port of the first swirl section being a non-fixed end.

In one or more embodiments of the mixer, the mixing assembly extends along an axis and the outlet is symmetrical along the axis.

An exhaust system according to an aspect of the present invention includes the mixer and the injector of any one of the above, the injector injecting a spray of reducing agent to the mixer.

In one or more embodiments of the exhaust system, the reductant spray is a urea solution spray.

In one or more embodiments of the exhaust system, the exhaust system further includes a first portion and a second portion, the first portion is connected to the air inlet portion of the mixer, the second portion is connected to the air outlet portion of the mixer, and the first portion, the second portion and the mixer form an exhaust system with a U-shaped structure.

In one or more embodiments of the exhaust system, the second portion includes a selective catalytic reduction reactor with an orifice plate disposed between the selective catalytic reduction reactor and the mixer.

An internal combustion engine arrangement according to one aspect of the present invention comprises an internal combustion engine and an exhaust system as described in any one of the above for treating exhaust gas produced by the internal combustion engine.

The utility model discloses an advance effect includes but is not limited to, through on the basis of first whirl section, first mixing section, the low reaches set up second whirl section and second mixing section, realize the secondary whirl of blender for the mixing uniformity of blender is good, the urea crystallization rate is low, and exhaust system and internal-combustion engine equipment's nitrogen oxide discharges and satisfies the demands.

Drawings

The above and other features, properties and advantages of the present invention will become more apparent from the following description of the embodiments with reference to the accompanying drawings, it being noted that the drawings are given by way of example only and are not drawn to scale, and should not be taken as limiting the scope of the invention, which is actually claimed, wherein:

fig. 1A and 1B are schematic structural views of an exhaust system according to an embodiment.

Fig. 2 is an exploded view of the mixer according to an embodiment.

FIG. 3 is a schematic diagram of a mixing assembly and an injector of the mixer of an embodiment.

FIG. 4 is a schematic diagram of a mixing assembly of the mixer of an embodiment from a side view.

FIG. 5 is a schematic top view of a mixer according to an embodiment.

Fig. 6A and 6B are schematic structural diagrams of the first cyclone section according to an embodiment.

Fig. 7A and 7B are schematic structural diagrams of a first cyclone section according to another embodiment.

FIG. 8 is a schematic diagram of a first straight section of a mixer according to an embodiment.

FIG. 9 is a schematic structural view of the second and third straight tube sections of the mixer of an embodiment.

FIGS. 10A and 10B are schematic structural views of a swirl assembly of a second swirl vane section of a mixer according to an embodiment.

Fig. 11A, 11B, 11C, and 11D are schematic structural views of the swirler vanes of the swirler assemblies shown in fig. 10A and 10B.

FIG. 12 is a schematic view of an orifice plate of an exhaust system according to an embodiment.

Detailed Description

The following discloses many different embodiments or examples for implementing the subject technology described. Specific examples of components and arrangements are described below to simplify the disclosure, but are by way of example only and are not limiting as to the scope of the invention.

It is noted that in the following description, for example, a "one embodiment," "one or more embodiments," and/or "some embodiments" means a feature, structure, or characteristic described in connection with at least one embodiment of the application. Therefore, it is emphasized and should be appreciated that two or more references to "an embodiment" or "some embodiments" or "one or more embodiments" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, certain features, structures, or characteristics may be combined as suitable in one or more embodiments of the application. The terms "first," "second," "third," and the like do not denote any order of importance, but rather are used for ease of description.

Referring to fig. 1A and 1B, in one embodiment, the exhaust system 100 includes a first portion 10, a second portion 20, and a mixer 1, which form a compact U-shaped exhaust system. It will be appreciated that the arrangement of the first section 10, the second section 20 and the mixer 1 is not limited to the U-shaped configuration shown in the figures, but may be, for example, an in-line configuration, which is advantageous in terms of compactness. With continued reference to fig. 1A and 1B, exhaust gas is treated in a first portion 10 from the inlet portion of the mixer 1 into the mixer, an injector 2 injects a reducing agent, typically a urea solution, into the mixer, where the exhaust gas and urea mix and create a swirling or spinning motion, and the swirling gas is discharged from the outlet portion of the mixer into a second portion 20. The first portion 10 may include a Diesel Oxidation Catalyst 101 (DOC) for treating unburned hydrocarbon and carbon monoxide in the exhaust gas, and may further include a Diesel Particulate Filter (DPF) disposed downstream of the Diesel Oxidation Catalyst 101 for reducing particulates in the exhaust gas. The second section 20 may include a selective catalytic reduction reactor 201 (hereinafter, referred to as SCR). It is understood that the terms "diesel oxidation catalyst" and "diesel particulate trap" are not intended to be limiting, but are used to refer to the exhaust component of a diesel engine, and for example, if the exhaust system of a gasoline engine is rich in unburned hydrocarbons and particulate pollutants due to lean burn and direct injection technologies, the exhaust system of the gasoline engine may also adopt "diesel oxidation catalyst" and "diesel particulate trap" as the exhaust component.

Referring to fig. 2-5, in some embodiments, mixer 1 includes a mixing assembly 11, mixing assembly 11 including a first swirl section 111, a first mixing section 121, a second swirl section 112, and a second mixing section 122. Therein, the first swirl section 111 has an inlet opening 1110, the inlet opening 1110 being used for providing an inlet for exhaust gas into the mixing space S of the mixer 1. The first mixing section 121 is located downstream of the first swirl section 111 and is fluidly connected adjacent to the first swirl section 111. The second swirl section 112 is located downstream of the first mixing section 121 and is fluidly connected adjacent to the first mixing section 121. The second mixing section 122 is located downstream of the second cyclone section 112 and is fluidly connected adjacent to the second cyclone section 112.

"swirl section" and "mixing section" are used herein to refer to the primary function performed by this section, but other functions are not entirely excluded. The main function achieved, for example, in the "first swirl section" and the "second swirl section" is to provide and to enhance the swirling motion of the gas flow, and the main function achieved in the "first mixing section" and the "second mixing section" is to achieve a homogeneous mixing of the exhaust gases with the urea and the ammonia from the urea decomposition, but not to exclude other functions. Mixing of the exhaust gases with the urea and the ammonia from the urea decomposition also takes place, for example, in the "first cyclone section" and the "second cyclone section". By "mixing space of the mixer" is meant here the process space in which mixing of exhaust gases with urea mainly takes place in the mixer 1, as opposed to the mixing space, the mixer may also provide a flow space F, i.e. a flow space for the mixer gas flow after thorough mixing of the exhaust gases with urea and ammonia from the decomposition of urea. "inlet opening" means that most of the exhaust gas enters from the inlet opening, but it is difficult to avoid that a very small part of the exhaust gas enters the mixing space from other places or gaps. In addition, the concepts of upstream and downstream are based on the direction of flow of exhaust gas in the exhaust system 100.

After entering the mixer 1, the exhaust enters the first swirling section 111 through the air inlet 1110 and enters the mixing space S to form swirling exhaust, the swirling exhaust is mixed with the injected urea spray at the downstream first mixing section 121, then passes through the downstream second swirling section 112, the swirling motion is further strengthened in the same direction or reversed, so that the droplets of the urea spray are fully decomposed, and then passes through the downstream second mixing section 122, the exhaust and the urea are further uniformly mixed, and the mixing effect is optimized. It should be noted that, in the course of completing the present application, the inventor finds that the second cyclone segment 112 and the first cyclone segment 111 can play a role in enhancing the mixing uniformity regardless of whether the cyclone directions are the same or opposite, and are selected according to the actual mixing uniformity requirement and the requirement of back pressure. In the structure shown in the figure, the swirling directions of the second swirling section 112 and the first swirling section 111 are opposite, so that the effect of enhancing the mixing uniformity is good, but the back pressure is increased to a certain degree, and the structure can be suitable for occasions with high requirements on the mixing uniformity. The swirling direction of the second swirling section 112 is the same as that of the first swirling section 111, the swirling motion equidirectional reinforcement can also achieve the effect of improving the mixing uniformity, although the effect of swirling motion reversal caused by the fact that the swirling directions are opposite is not obvious, the influence on the back pressure is small, therefore, if the structure that the swirling directions of the second swirling section 112 and the first swirling section 111 are the same can meet the requirement of the mixing uniformity, the structure that the swirling directions of the second swirling section 112 and the first swirling section 111 are the same can be preferentially adopted, and the influence on the exhaust back pressure is reduced.

The mixer 1 of the above embodiment is adopted, and the beneficial effect is that the inventor finds that, in the process of completing the present application, for the mixing component of the mixer with only the first swirling section and the first mixing section, the mixing effect on the existence of urea crystals and exhaust gas is not good under some working conditions (the indexes are ammonia uniformity, NH ₃ Uniformity Index). On the basis of the first rotational flow section and the first mixing section, the second rotational flow section and the second mixing section are arranged at the downstream, so that secondary rotational flow of the mixer is realized, the mixing uniformity of the mixer is good, the urea crystallization rate is low, and the emission of nitrogen oxides of an exhaust system and internal combustion engine equipment meets the requirements.

With continued reference to fig. 2-5, in some embodiments, first cyclone section 111 includes a cyclone cone 1111, a sidewall of cyclone cone 1111 has a plurality of air inlet openings 1110, and the plurality of air inlet openings 1110 are distributed along a circumferential direction of cyclone cone 1111, as shown in fig. 3, a small end port 1112 of cyclone cone 1111 is an injection opening for providing an inlet for a reductant spray, such as a urea spray, into mixing space S of mixer 1. The large end port 1113 of the swirl cone 1111 is fluidly connected adjacent to the upstream end of the first mixing section 121. Adopt the cyclone cone 1111 and the exhaust of above embodiment to get into from the lateral wall of cyclone cone 1111, and the structure that the reductant spraying got into from the tip of cyclone cone 1111, easily constructs the stronger exhaust whirl at first whirl section to the spray of urea spraying can fully extend, easily by the decomposition and fully contact with the exhaust, prevents urea crystallization, optimizes the mixed effect.

With continuing reference to fig. 2 to 5, and fig. 6A, 6B, and fig. 7A, 7B, in one or more embodiments, the structure of the first cyclone section 111 for realizing stronger exhaust cyclone may further include providing cyclone blades 1114 at the air inlet 1110, where the number of the cyclone blades 1114 is not limited to that shown in the figures, for example, one cyclone blade 1114 is provided for each air inlet 1110 in the embodiment shown in the figures, but may actually be adjusted according to the requirement of different cyclone strengths, for example, only some air inlets 1110 may be provided with the cyclone blades 1114. Further, comparing fig. 6A and 6B, fig. 7A and 7B, the orientation of the swirl vanes 1114 can also be flexibly set according to the direction, strength and space requirement of the swirl flow which can be constructed as required. As shown in fig. 6A and 6B, in one embodiment, the swirl vanes 1114 extend in the outer direction of the swirl cone 1111, while in another embodiment, as shown in fig. 7A and 7B, the swirl vanes 1114 extend in the inner direction of the swirl cone 1111, which can achieve a stronger exhaust swirl.

With continued reference to fig. 2-5, and also to fig. 8, in some embodiments, the specific structure of the first mixing section 121 may be a first straight pipe section 1211, an upstream end of the first straight pipe section 1211 is connected with a downstream end of the first cyclone section 111, and a downstream end of the first straight pipe section 1211 is connected with the second cyclone section 112. The advantage of using the above embodiment is the simple structure of the first mixing section 121.

With continuing reference to fig. 3, 4, 8 and 9, in some embodiments, the first mixing section 121 further includes a second straight pipe section 1212, the second straight pipe section 1212 is fixedly sleeved on the first straight pipe section 1211 at a radial outer side of the first straight pipe section 1211, and a radial gap between the first straight pipe section 1211 and the second straight pipe section 1212 provides the exhaust bypass passage P, which has an advantage that exhaust gas flowing in the exhaust bypass passage P can provide a heating effect on a wall surface of the first straight pipe section 1211 to thermally decompose liquid droplets or liquid films of the urea spray retained in the first straight pipe section 1211, so as to reduce urea crystals. The specific structure of the second straight tube section 1212 fixed to the first straight tube section 1211 at the radial outside of the first straight tube section 1211 can be, but not limited to, the structure shown in fig. 3 and 4, and is fixedly connected by a plurality of recesses 12120 radially inward of the second straight tube section 1212.

With continued reference to fig. 3, 4, and 8, 9, in one or more embodiments, the second straight tube section 1212 integrally extends downstream of a third straight tube section 1213, the third straight tube section 1213 providing space for the second swirl section 112 and/or the second mixing section 122. As shown in fig. 3 and 9, such an advantageous effect is that multiple functions of the gas bypass passage P, the second cyclone section 112, the second mixing section 122, and the like can be provided only through the space of a single pipe, so that the mixer is simple and compact in structure.

Referring to fig. 3, and as shown in fig. 10A and 10B, in some embodiments, the specific structure of the second cyclone section 112 may be that the second cyclone section 112 includes a pipe section 1120 and a cyclone assembly 1121 located within the pipe section 1120, the cyclone assembly 1121 including a plurality of cyclone blades 1122 radiating outwardly from a center C of the pipe section 1120. As shown in fig. 3 and 9, the tube section 1120 may be part of the third straight tube section 1213, i.e. the third straight tube section 1213 comprises the tube section 1120. With the cyclone assembly 1121 of such a structure, the plurality of cyclone blades 1122 radiating outward from the center C of the pipe segment 1120 can sufficiently break up the liquid droplets and the liquid film of the urea spray, further promote the decomposition of the urea spray, reduce the urea crystallization, and optimize the mixing effect.

Referring to fig. 9 and 10A, 10B, and 11A-11D, in one or more embodiments, swirl vanes 1122 include a body portion 1123 and a connecting portion 1124; the connecting part 1124 comprises a first connecting part 11241 and a second connecting part 11242 which are respectively positioned at the two radial ends of the body part 1123, and the connecting part 1124 extends in the circumferential direction and is fixedly connected with the pipe section 1120; the body 1123 comprises a first body 11231 and a second body 11232 extending from the central portion 11230 to the two ends in the radial direction, and the first body 11231 and the second body 11232 have a swirling surface and a swirling streamline. The hub 11230 has slots 11234, and each swirl vane 1122 is connected by plugging of the slots 11234 of the hub. The connection portion 1124 is configured such that the swirl vanes 1122 can be fixed to the second swirl section 112 without the need of fixing the swirl assembly 1121 through shaft support, for example, as shown in fig. 3 and 9, the connection portion 1124 is connected to the pipe section 1120 through a plug-weld structure 1125, that is, a welding spot is formed at the periphery of the exhaust gas and urea mixing region of the second swirl section 112 configured by the swirl assembly 1121, so that urea crystallization can be reduced. The principle is that the inventor finds in the process of completing the present application that the common location of urea crystals is the welded spot. Likewise, each swirl vane 1122 is plugged into the slot 11234 at the center, rather than welded, to reduce the amount of welding at the exhaust and urea mixing region of the second swirl section 112 of the swirl assembly 1121, thereby reducing urea crystallization.

Referring to fig. 1A, 2 and 5, in some embodiments, the mixer 1 further includes a cover 12 and a base 13 in addition to the mixing component 11, the cover 12 and the base 13 define a flow space F of the mixer 1, the mixing component 11 is located inside the flow space F, the base 13 has an air inlet 14 and an air outlet 15 of the mixer 1, taking the upstream of the mixer 1 corresponding to the DPF and the downstream corresponding to the SCR as an example, the exhaust passing through the DPF enters the flow space F of the mixer from the air inlet 14 and then enters the mixing space from the air inlet 1110 of the mixer 1, and after being sufficiently mixed with the urea spray, the mixed air flow is exhausted from the air outlet 15 to the SCR to convert nitrogen oxides into nitrogen and water. As shown in fig. 2, the cover 12 may include an inner cover 121, an insulation layer 122, and an outer cover 123, which may serve as an insulation for the mixer 1. In some embodiments, the injector 2 is located in an injector mounting hole 124 of the outer cover 12, the injector 2 is mounted to the outer cover 12 through an injector mounting seat 125, the injector mounting hole 124 is communicated with the first cyclone section 111, the first cyclone section 111 has an air inlet end of the mixing component 11 and is communicated with the air inlet portion 14 of the mixer 1, the second mixing section 122 has an air outlet end of the mixing component 11 and is communicated with the air outlet portion 15 of the mixer, namely, the exhaust gas and the urea spray enter the mixing space at the first cyclone section 111 until reaching the second mixing section 122, and the urea crystallization is further reduced and the mixing effect is optimized.

With continued reference to fig. 2 and 5, in some embodiments, the mixer 1 further has a partition 16, the partition 16 separates the air inlet 14 and the air outlet 15 of the mixer 1, and the mixing component 11 is supported by the partition 16, one end port of the first cyclone segment 111 is an injection opening for providing an inlet of the reducing agent spray into the mixing space of the mixer, for example, the small end port 1112 of the cyclone cone 1111 is an injection opening, and the end port of the first cyclone segment 111 is a non-fixed end, that is, the mixing component 11 is fixed in the mixer 1 by the support of the partition 16, but not fixedly connected to the end port of the first cyclone segment 111 by welding or the like, for example, the small end port outer cover 1112 12 of the cyclone cone 1111 and/or the mixer mounting seat 125 and/or the injector mounting hole 124 have a gap, which can improve the structural reliability of the mixer 1 and facilitate processing. The principle of the method is that in the process of completing the application, the inventor finds that if the port of the first cyclone section 111 is welded and fixed with the outside, the connecting structure is easy to fail due to thermal stress fatigue in the operation process, and the clearance can also allow the mixing assembly, the outer cover and the injector to have certain machining errors and not interfere with each other, so that the mixing assembly is convenient to machine. However, it will be appreciated by those skilled in the art that the gap should not be too large, and if the gap is too large, the proportion of exhaust gas entering the first cyclonic section from the gap rather than the inlet opening will increase, which is detrimental to the construction of the cyclonic motion of the exhaust gas, and therefore the upper limit of the gap may be determined by simulation or experimentation to ensure that the intensity requirements of the cyclonic motion of the exhaust gas are met. In addition, the air inlet part 14 and the air outlet part 15 of the mixer 1 are separated by the partition plate 16, so that the mixing effect can be further optimized, and the mixed air flow discharged from the air outlet end of the mixing component 11 is prevented from flowing back to the air inlet end of the mixing component 11 again.

With continued reference to fig. 5, in one or more embodiments, the mixing component 11 may be configured such that the mixing component 11 extends along an axis A1, and the gas outlet 15 of the mixer 1 is symmetrical along the axis A1, which has the effect that, as shown in fig. 5, the gas flow flowing out of the mixing component 11 can be divided into two swirling flows M1, M2, so that the exhaust gas and the reducing component in the mixed gas flow can be mixed well and can be easily and uniformly attached to the SCR reactive sites. It will be appreciated by those skilled in the art that the mixer 1 is not limited to the outlet 15 being symmetrical along the axis A1, for example, when it is required to meet different layout space requirements, it is possible to arrange the outlet 15 offset with respect to the position shown in fig. 5, and when the outlet 15 is asymmetrical along the axis A1, additional measures can be taken to improve the uniformity of the gas flow.

With continued reference to fig. 5 and 12, in some embodiments, an orifice 17 is disposed between the SCR and the mixer, so that the uniformity of the mixture gas flow reaching the SCR for reaction is better, and the inventor has found in the process of completing the present application that the effect of improving the nitrogen oxide treatment effect is particularly significant for the structure of the exhaust system with a larger volume of the SCR or the structure with the upstream end surface of the SCR being far from the gas outlet 15. For another example, as mentioned above, when it is required to meet the requirements of different arrangement spaces, it is possible to dispose the air outlet 15 in a manner of being offset with respect to the position shown in fig. 5, in which case the air outlet 15 is asymmetric along the axis A1, and in which case the orifice 17 may be disposed to improve the uniformity of the air flow. For some SCR with smaller volume or the structure that the upstream end face of the SCR is far from the air outlet 15, the uniformity of the mixed gas flow can generally meet the requirement, so the orifice plate 17 can also be omitted. The specific position of the orifice 17 between the SCR and the mixer can be, as shown in fig. 5, next to the outlet 15, or can be located inside the second section 20 and closer to the SCR, and is adjusted according to actual needs.

In view of the above, according to some embodiments of the present application, the present application further provides an internal combustion engine apparatus, including the exhaust system described in the above embodiments and an internal combustion engine, the exhaust system being configured to process exhaust gas generated by the internal combustion engine.

The internal combustion engine equipment includes, but is not limited to, vehicles using an internal combustion engine as power, such as vehicles, including passenger vehicles, commercial vehicles, engineering machinery, agricultural machinery, rail transit trains, and the like, and the vehicles may also include, for example, ships, aircrafts, and the like using the internal combustion engine as power, and the internal combustion engine equipment also includes power generation systems using the internal combustion engine as power, such as a diesel generator system, a biogas generator set of a biogas power plant, and exhaust gas generated by the internal combustion engine of the vehicles and the power generation systems is treated by an exhaust system in order to meet requirements of relevant emission regulations of the vehicles and the power generation systems.

In view of the above, the mixer, the exhaust system and the internal combustion engine apparatus described in the above embodiments have the beneficial effects that, but not limited to, the second swirling flow section and the second mixing section are arranged downstream on the basis of the first swirling flow section and the first mixing section, so that the secondary swirling flow of the mixer is realized, the mixing uniformity of the mixer is good, the urea crystallization rate is low, and the nitrogen oxide emission of the exhaust system and the internal combustion engine apparatus meets the requirement.

Although the present invention has been described with reference to the above embodiments, it is not intended to limit the present invention, and those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent changes and modifications made to the above embodiments according to the technical spirit of the present invention, all without departing from the content of the technical solution of the present invention, fall within the scope of protection defined by the claims of the present invention.

Claims (18)

1. A mixer (1) for an exhaust system (100), comprising a mixing assembly (11), the mixing assembly (11) comprising:

a first swirl section (111) having an inlet opening (1110), the inlet opening (1110) for providing an inlet for exhaust gas into a mixing space (S) of the mixer (1);

a first mixing section (121) downstream of the first swirl section (111) and fluidly connected adjacent to the first swirl section (111);

a second swirl section (112) downstream of the first mixing section (121) and fluidly connected adjacent to the first mixing section (121), the second swirl section (112) being in the same or opposite swirl direction as the first swirl section (111); and

a second mixing section (122) downstream of the second swirl section (112) and fluidly connected adjacent to the second swirl section (112).

2. A mixer (1) according to claim 1, wherein the first swirl section (111) comprises a swirl cone (1111), the side wall of the swirl cone (1111) having a plurality of the air inlet openings (1110), the plurality of air inlet openings (1110) being distributed along the circumferential direction of the swirl cone (1111), the small end port (1112) of the swirl cone (1111) being an injection opening for providing an inlet for a spray of reducing agent into the mixing space (S) of the mixer (1), the large end port (1113) of the swirl cone (1111) being fluidly connected adjacent to the upstream end of the first mixing section (121).

3. A mixer (1) as claimed in claim 2, in which the inlet opening (1110) is provided with first swirl vanes (1114).

4. A mixer (1) as claimed in claim 1, wherein the first mixing section (121) comprises a first straight tube section (1211), an upstream end of the first straight tube section (1211) being connected with a downstream end of the first cyclone section (111), a downstream end of the first straight tube section (1211) being connected with the second cyclone section (112).

5. The mixer (1) according to claim 4, wherein the first mixing section (121) further comprises a second straight pipe section (1212), the second straight pipe section (1212) being sleeved on the first straight pipe section (1211) radially outside the first straight pipe section (1211), a radial gap between the first straight pipe section (1211) and the second straight pipe section (1212) providing the exhaust bypass channel (P).

6. A mixer (1) according to claim 5, wherein the second straight tube section (1212) extends downstream a third straight tube section (1213), the third straight tube section (1213) providing space for the second swirl section (112) and/or second mixing section (122).

7. A mixer (1) according to claim 1, wherein the second swirl section (112) comprises a tube section (1120) and a swirl assembly (1121) located within the tube section (1120), the swirl assembly (1121) comprising a plurality of second swirl vanes (1122) radiating outwardly from the centre of the tube section (1120).

8. A mixer (1) as claimed in claim 7, wherein the second swirl vane (1122) comprises a body (1123) and a connecting portion (1124); the connecting part (1124) comprises a first connecting part (11241) and a second connecting part (11242) which are respectively positioned at the two radial ends of the blade body part (1123), and the connecting part (1124) extends in the circumferential direction and is fixedly connected with the pipe section (1120); the body part (1123) comprises a first body part (11231) and a second body part (11232) which extend from a central part (11230) to two radial ends respectively, the first body part (11231) and the second body part (11232) are provided with swirl surfaces, the central part (11230) is provided with inserting grooves (11234), and each second swirl vane (1122) is connected through the central part (11230) in an inserted mode.

9. A mixer (1) according to claim 8, wherein the third straight pipe section (1213) comprises this pipe section (1120), and the connection (1124) of the second swirl vanes (1122) is connected to the pipe section (1120) by means of a plug weld structure (1125).

10. A mixer (1) as claimed in claim 1, wherein the mixer (1) further comprises an outer cover (12), a base (13), the outer cover (12) and the base (13) defining a flow space (F) of the mixer (1), the mixing assembly (11) being located in the flow space (F), the base (13) having an inlet portion (14) and an outlet portion (15) of the mixer (1).

11. A mixer (1) as claimed in claim 10, wherein the outer cover (12) has an injector mounting hole (124), the injector mounting hole (124) communicating with the first cyclone segment (111), the first cyclone segment (111) having an inlet end of the mixing assembly (11) communicating with the inlet portion (14) of the mixer (1), the second mixing segment (122) having an outlet end of the mixing assembly (11) communicating with the outlet portion (15) of the mixer (1).

12. A mixer (1) as claimed in claim 10, wherein the mixer (1) further has a partition (16), the partition (16) separating an inlet (14) and an outlet (15) of the mixer (1), and the mixing assembly (11) being supported by the partition (16), the end port of the first cyclone section (111) being an injection opening for providing an inlet for a spray of reducing agent into the mixing space of the mixer, the end port of the first cyclone section (111) being a non-fixed end.

13. A mixer (1) as claimed in claim 10, wherein the mixing assembly (11) extends along an axis (A1) and the outlet (15) is symmetrical along this axis (A1).

14. An exhaust system (100) comprising a mixer (1) according to any of claims 1-13 and an injector (2), the injector (2) being adapted to inject a spray of reducing agent into the mixer (1).

15. An exhaust system (100) according to claim 14, wherein the reductant spray is a urea solution spray.

16. An exhaust system (100) according to claim 14, further comprising a first part (10) and a second part (20), wherein the first part (10) is connected with the inlet part (14) of the mixer (1), the second part (20) is connected with the outlet part (15) of the mixer (1), and the first part (10), the second part (20) and the mixer (1) form the exhaust system (100) with a U-shaped structure.

17. An exhaust system (100) according to claim 16, characterized in that the second portion (20) comprises a selective-catalytic-reduction reactor (201), between which selective-catalytic-reduction reactor (201) and the mixer (1) an aperture plate (17) is arranged.

18. An internal combustion engine arrangement, comprising an internal combustion engine, and an exhaust system according to any of claims 14-17 for treating exhaust gases produced by the internal combustion engine.

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