阅读说明：本技术 一种后处理结构故障诊断的方法及后处理结构 (Method for diagnosing faults of post-processing structure and post-processing structure ) 是由 蒋学锋 陈小迅 张衡 陈旭 冯坦 何胜勇 陈镇 于 2020-06-29 设计创作，主要内容包括：本申请涉及一种后处理结构故障诊断的方法及后处理结构,涉及发动机尾气净化技术领域,该后处理结构包括颗粒物捕捉器,与颗粒物捕捉器通过排气管连通的选择性催化还原器；其包括以下步骤：在排气管上开设一检查口；在检查口上设一连接筒,以使连接筒的检测通道与排气管相连通；在检测通道内植入一检测装置,以使检测装置朝向选择性催化还原器；通过检测装置检测该选择性催化还原器,以判断选择性催化还原器是否发生结晶堵塞。能直接准确诊断选择性催化还原器是否发生了结晶故障,并针对性对选择性催化还原器进行结晶故障维修,便于后续的维修,减少维修成本和时间。(The application relates to a method for diagnosing faults of a post-processing structure and the post-processing structure, relating to the technical field of engine tail gas purification, wherein the post-processing structure comprises a particulate matter catcher and a selective catalytic reduction device communicated with the particulate matter catcher through an exhaust pipe; which comprises the following steps: an inspection opening is formed in the exhaust pipe; a connecting cylinder is arranged on the inspection opening so as to enable a detection channel of the connecting cylinder to be communicated with the exhaust pipe; implanting a detection device in the detection channel so that the detection device faces the selective catalytic reduction device; the selective catalytic reducer is detected by a detection device to judge whether the selective catalytic reducer is blocked by crystallization. The method can directly and accurately diagnose whether the selective catalytic reduction device has crystallization faults or not, and pertinently maintain the selective catalytic reduction device for crystallization faults, thereby facilitating subsequent maintenance and reducing maintenance cost and time.)

1. A method of diagnosing a malfunction of an aftertreatment structure including a particulate matter trap (1), a selective catalytic reduction device (3) communicating with the particulate matter trap (1) through an exhaust pipe (2); it is characterized by comprising the following steps:

an inspection opening (20) is formed in the exhaust pipe (2);

a connecting cylinder (5) is arranged on the inspection opening (20) so that a detection channel (50) of the connecting cylinder (5) is communicated with the exhaust pipe (2);

implanting a detection device (4) in the detection channel (50) so that the detection device (4) faces the selective catalytic reduction device (3);

and detecting the selective catalytic reducer (3) through the detection device (4) to judge whether the selective catalytic reducer (3) is blocked by crystallization.

2. The method of aftertreatment structure fault diagnosis of claim 1, the method further comprising the steps of:

detecting whether the particle trap (1) is clogged.

3. The method for fault diagnosis of an aftertreatment structure according to claim 2, wherein detecting whether the particulate matter trap (1) is clogged comprises the following steps:

connecting a differential pressure sensor (6) at both ends of the particulate matter trap (1) to detect a differential pressure at both ends of the particulate matter trap (1);

and judging whether the particulate matter catcher (1) is blocked or not according to the relation between the pressure difference and the preset pressure difference.

4. The method for diagnosing faults of an aftertreatment structure according to claim 1, characterized in that after detecting whether the selective catalytic reducer (3) is blocked by crystallization, it further comprises the steps of:

-extracting the detection device (4);

a sealing element (7) is connected to the connecting cylinder (5) in order to close off the detection channel (50).

5. The method for fault diagnosis of an aftertreatment structure according to claim 4, wherein the sealing element (7) is a bolt screwed into the connecting cylinder (5), or wherein the sealing element (7) is a sleeve fitted over the connecting cylinder (5) by means of a collar, or wherein the detection device (4) is screwed into the connecting cylinder (5).

6. The method of aftertreatment structure fault diagnosis according to claim 1, characterized in that the connecting cylinders (5) are arranged obliquely so that the axes of the connecting cylinders (5) and the axis of the selective catalytic reducer (3) are at an obtuse angle.

7. Method of fault diagnosis of an aftertreatment structure according to claim 1, characterized in that the detection device (4) comprises:

a pressure sensor (40) extending into the detection passage (50) and detecting a pressure at an inlet of the selective catalytic reducer (3);

and the controller (41) is connected with the pressure sensor (40) and is used for judging whether the selective catalytic reducer (3) is blocked by crystallization or not according to the comparison of the pressure detected by the pressure sensor (40) and a preset pressure value.

8. Method of fault diagnosis of an aftertreatment structure according to claim 1, characterized in that the detection device (4) comprises:

an endoscope extending into the detection channel (50) and used for taking a picture of the internal structure of the selective catalytic reduction device (3);

and the display is connected with the endoscope and is used for displaying the picture shot by the endoscope so as to be used for a maintainer to judge whether the selective catalytic reduction device (3) is blocked by crystallization.

9. An aftertreatment structure, comprising:

a particulate matter trap (1);

a selective catalytic reduction device (3) which is communicated with the particulate matter trap (1) through an exhaust pipe (2); an inspection opening (20) is formed in the exhaust pipe (2);

a connecting cylinder (5) which is internally provided with a detection channel (50) penetrating through the connecting cylinder (5), wherein the connecting cylinder (5) is arranged on the inspection opening (20) so as to enable the detection channel (50) to be communicated with the exhaust pipe (2);

a seal (7) connected to the connecting cylinder (5) to seal off the detection channel (50).

10. An aftertreatment structure according to claim 9, further comprising a detection device (4), the detection device (4) and the seal (7) being alternatively connected to the connector barrel (5).

Technical Field

The application relates to the technical field of engine tail gas purification, in particular to a method for diagnosing faults of an aftertreatment structure and the aftertreatment structure.

Background

Along with the requirement on particle emission and nitrogen oxide NOx emission is tightened, in order to meet regulated emission, a vehicle can be matched with an after-treatment system, the after-treatment system consists of an oxidation catalyst DOC, a particulate matter catcher DPF, a selective catalytic reduction device SCR and an ammonia oxidation catalyst ASC, the problems of carbon blockage and ash blockage easily occur in the use process of the DPF, the problem of crystallization blockage easily occurs in the use process of the SCR, and the two faults can cause the exhaust backpressure of an engine to be high and influence the performance of the engine. However, since the two faults behave the same, the two faults cannot be distinguished accurately, which may result in failure to diagnose the cause of the fault accurately.

At present, in order to solve the problem of high exhaust backpressure of an engine, a DPF is generally detached to determine whether the blockage occurs, and if the blockage occurs, the blockage fault of the DPF is maintained; if the DPF is not blocked, the SCR crystal fault is directly considered, and corresponding maintenance is carried out.

However, this method can only diagnose whether DPF is blocked or not, and cannot diagnose whether SCR is crystallized and blocked or not, and DPF is not blocked, which is directly regarded as SCR crystallization fault and carries out crystallization fault maintenance on SCR, and it is very likely that SCR is not crystallized and fault is still not solved, which results in overlong diagnosis time, overhigh diagnosis cost, increased maintenance cost and increased maintenance time for customers, and causes customer complaints; and then, the SCR crystallization fault is directly judged by not generating the DPF blockage fault, so that misdiagnosis is caused, and the maintenance is invalid.

Disclosure of Invention

The embodiment of the application provides a fault diagnosis method for a post-processing structure and the post-processing structure, which are used for solving the problems that in the related art, due to the fact that whether the SCR has a crystallization fault or not can not be accurately diagnosed, the SCR is directly considered as the crystallization fault when a DPF is not blocked, and the crystallization fault is maintained on the SCR, the fault can not be solved, the diagnosis time is too long, and the diagnosis cost is too high.

In a first aspect, a method of fault diagnosis of an aftertreatment structure including a particulate trap, a selective catalytic reducer in communication with the particulate trap through an exhaust pipe; which comprises the following steps:

an inspection opening is formed in the exhaust pipe;

a connecting cylinder is arranged on the inspection opening so as to enable a detection channel of the connecting cylinder to be communicated with the exhaust pipe;

implanting a detection device in the detection channel so that the detection device faces the selective catalytic reducer;

and detecting the selective catalytic reducer through the detection device to judge whether the selective catalytic reducer is blocked by crystallization.

In some embodiments, the method further comprises the steps of:

detecting whether the particulate matter trap is clogged.

In some embodiments, detecting whether the particulate trap is clogged specifically includes the steps of:

connecting a differential pressure sensor at two ends of the particle catcher to detect the pressure difference at two ends of the particle catcher;

and judging whether the particulate matter catcher is blocked or not according to the relation between the pressure difference and the preset pressure difference.

In some embodiments, after detecting whether the selective catalytic reducer is blocked by crystallization, the method further comprises the following steps:

taking out the detection device;

and connecting a sealing element on the connecting cylinder to seal off the detection channel.

In some embodiments, the sealing element is a bolt screwed into the connecting cylinder, or the sealing element is a sleeve sleeved on the connecting cylinder through a clamp, or the detection device is screwed into the connecting cylinder.

In some embodiments, the connecting cylinder is disposed at an inclination such that an axis of the connecting cylinder and an axis of the selective catalytic reducer form an obtuse angle.

In some embodiments, the detection device comprises:

a pressure sensor extending into the detection passage and detecting a pressure at an inlet of the selective catalytic reducer;

and the controller is connected with the pressure sensor and is used for judging whether the selective catalytic reducer is crystallized and blocked or not according to the comparison of the pressure detected by the pressure sensor and a preset pressure value.

In some embodiments, the detection device comprises:

the endoscope extends into the detection channel and is used for taking a picture of the internal structure of the selective catalytic reduction device;

and the display is connected with the endoscope and used for displaying the picture shot by the endoscope so as to be used for a maintainer to judge whether the selective catalytic reduction device is blocked by crystallization.

In a second aspect, there is provided a post-processing structure comprising:

a particulate matter trap;

the selective catalytic reduction device is communicated with the particulate matter catcher through an exhaust pipe; an inspection opening is formed in the exhaust pipe;

the connecting cylinder is internally provided with a detection channel penetrating through the connecting cylinder, and the connecting cylinder is arranged on the inspection opening so as to enable the detection channel to be communicated with the exhaust pipe;

and the sealing element is connected with the connecting cylinder to seal off the detection channel.

In some embodiments, the aftertreatment structure further comprises a sensing device that is alternatively coupled to the connector barrel with the seal.

The beneficial effect that technical scheme that this application provided brought includes: the method can directly and accurately diagnose whether the selective catalytic reduction device has crystallization faults or not, and pertinently maintain the selective catalytic reduction device for crystallization faults, thereby facilitating subsequent maintenance and reducing maintenance cost and time.

The embodiment of the application provides a method for diagnosing faults of a post-processing structure and the post-processing structure. Therefore, the fault diagnosis method can directly and accurately diagnose whether the selective catalytic reduction device has the crystallization fault or not, and pertinently carries out crystallization fault maintenance on the selective catalytic reduction device, thereby facilitating subsequent maintenance and reducing the maintenance cost and time.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a flow chart of a method for diagnosing faults of a post-processing structure according to an embodiment of the present application;

fig. 2 is a schematic state diagram of a post-detection processing structure according to an embodiment of the present disclosure;

FIG. 3 is a schematic structural diagram of a post-processing structure according to an embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of a connector provided in an embodiment of the present application.

In the figure: 1. a particulate matter trap; 2. an exhaust pipe; 20. an inspection opening; 3. a selective catalytic reducer; 4. a detection device; 40. a pressure sensor; 41. a controller; 5. a connecting cylinder; 50. a detection channel; 6. a differential pressure sensor; 7. and a seal.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Referring to fig. 1 and 2, an embodiment of the present application provides a method of diagnosing a malfunction of an aftertreatment structure including a particulate matter trap 1, a selective catalytic reducer 3 communicating with the particulate matter trap 1 through an exhaust pipe 2; which comprises the following steps:

s1: an inspection port 20 is formed in the exhaust pipe 2, the inspection port 20 is close to the selective catalytic reduction device 3, and since the crystal blockage fault of the selective catalytic reduction device 3 can be diagnosed only by detecting the interior thereof, the inspection port 20 for the internal condition of the selective catalytic reduction device 3 needs to be formed in the exhaust pipe 2 close to the selective catalytic reduction device 3;

s2: a connecting cylinder 5 is arranged on the inspection opening 20, so that a detection channel 50 of the connecting cylinder 5 is communicated with the exhaust pipe 2; since the exhaust pipe 2, the particulate matter trap 1 and the selective catalytic reduction device 3 are welded, and the detection device 4 for detecting the selective catalytic reduction device 3 cannot be fixed on the inspection opening 20, the connection between the detection device 4 and the exhaust pipe 2 needs to be realized by means of the structure of the connecting cylinder 5;

s3: implanting a detection device 4 in the detection passage 50 such that the detection device 4 faces the selective catalytic reduction device 3; the detection device 4 extends into the detection passage 50 and faces the selective catalytic reducer 3 to detect the interior of the selective catalytic reducer 3;

s4: the selective catalytic reducer 3 is detected by the detection device 4 to determine whether or not crystal clogging has occurred in the selective catalytic reducer 3. When the vehicle has problems such as poor economy or insufficient power, it is inferred that the engine exhaust back pressure is high. Implanting a detection device 4 into the detection channel 50, then starting the vehicle, parking the vehicle, adjusting the rotating speed to 1500rpm, maintaining for a period of time (such as 5min), then detecting whether white crystal blocks exist in the selective catalytic reducer 3, and if the white crystal blocks are larger, determining that the selective catalytic reducer 3 has a crystallization fault. Therefore, the method for diagnosing the fault of the aftertreatment structure in the embodiment of the application can be finished not only in the vehicle parking state but also in the vehicle running state.

In the embodiment of the present application, the exhaust pipe 2 is provided with the inspection port 20, and the connecting cylinder 5 is fixed to the inspection port 20, and the selective catalytic reduction device 3 is detected by installing the detection device 4 in the connecting cylinder 5, so as to detect whether the selective catalytic reduction device 3 is crystal-blocked. The fault diagnosis method can directly and accurately diagnose whether the selective catalytic reduction device 3 has the crystallization fault, and pertinently carries out the crystallization fault maintenance on the selective catalytic reduction device 3, thereby facilitating the subsequent maintenance and reducing the maintenance cost and time.

Referring to fig. 2, preferably, the method further comprises the steps of:

s5: it is detected whether the particulate matter trap 1 is clogged. After judging whether the selective catalytic reduction device 3 has the crystallization blockage fault, whether the particulate matter catcher 1 is blocked needs to be detected again so as to accurately determine the reason that the exhaust back pressure of the engine is high and the reason is caused by the blockage of the particulate matter catcher 1, the crystallization blockage of the selective catalytic reduction device 3 or the blockage of the particulate matter catcher 1 and the selective catalytic reduction device 3, so that the targeted maintenance is carried out, the misjudgment is avoided, and the maintenance efficiency is improved.

Referring to fig. 2, preferably, the method for detecting whether the particulate matter trap 1 is blocked includes the following steps:

s51: a differential pressure sensor 6 is connected to both ends of the particulate matter trap 1 to detect a pressure difference between both ends of the particulate matter trap 1;

s52: and judging whether the particulate matter trap 1 is blocked or not according to the relation between the pressure difference and the preset pressure difference.

When the vehicle has problems such as poor economy or insufficient power, it is inferred that the engine exhaust back pressure is high. The two ends of the particulate matter catcher 1 are connected with a differential pressure sensor 6, a vehicle is parked, the rotating speed is adjusted to a target rotating speed (such as 1500rpm), the indicating number of the differential pressure sensor 6 is checked after the vehicle runs for a period of time (such as 5min), and if the differential pressure sensor 6 is larger than a preset pressure difference (such as 5kpa), the particulate matter catcher 1 is considered to have a blockage fault.

Referring to fig. 3, further, after detecting whether the selective catalytic reducer 3 is blocked by crystallization, the method further includes the following steps:

s6: taking out the detection device 4; the detection device 4 is detachably connected with the connecting cylinder 5, and the detection device 4 is screwed in the connecting cylinder 5;

s7: a seal 7 is attached to the connector barrel 5 to seal off the detection channel 50. When the selective catalytic reduction unit 3 is not required to be tested, the inspection port 20 needs to be sealed, and the inspection port 20 needs to be sealed by the sealing member 7.

Referring to fig. 4, further, the sealing member 7 is a bolt screwed into the connecting cylinder 5, or the sealing member 7 is a sleeve sleeved on the connecting cylinder 5 through a clamp. The connecting cylinder 5 can be plugged in the several ways, and the connecting cylinder 5 can be conveniently detached.

Preferably, the connecting cylinder 5 is disposed obliquely such that the axis of the connecting cylinder 5 makes an obtuse angle with the axis of the selective catalytic reduction device 3. By the design, the detection device 4 faces the selective catalytic reduction device 3 when extending into the detection channel 50, so that the interior of the selective catalytic reduction device 3 can be conveniently checked to judge whether the selective catalytic reduction device 3 has a crystallization blockage fault.

Further, the detecting device 4 includes a pressure sensor 40 and a controller 41, the pressure sensor 40 extends into the detecting passage 50 and is used for detecting the pressure at the inlet of the selective catalytic reducer 3; the controller 41 is connected to the pressure sensor 40 and is configured to determine whether or not the selective catalytic reducer 3 is crystal-clogged, based on a comparison between the pressure detected by the pressure sensor 40 and a preset pressure value. The bolts of the inspection port 20 are removed, then the pressure sensor 40 is fastened in the detection channel 50 through threads, then the vehicle is started, the vehicle is parked, the rotating speed is adjusted to be 1500rpm, after the rotating speed is maintained for a period of time (such as 5min), the pressure value collected by the pressure sensor 40 is received through the controller 41, and if the pressure value is larger than the preset pressure value (such as 5kpa), the selective catalytic reducer 3 is considered to have crystallization fault.

Further, the detecting device 4 includes an endoscope and a display, the endoscope is inserted into the detecting channel 50 and is used for taking a picture of the internal structure of the selective catalytic reduction device 3; the display is connected with the endoscope and is used for displaying pictures taken by the endoscope so as to be used by maintainers to judge whether the selective catalytic reduction device 3 is blocked by crystallization. The bolt of the inspection hole 20 is removed, the endoscope is fastened into the detection channel 50 through threads, the vehicle is started, the vehicle is parked, the rotating speed is adjusted to be 1500rpm, after the rotating speed is maintained for a period of time (such as 5min), the picture shot by the endoscope is displayed through the display, the picture is checked by a maintainer, whether white crystal blocks exist in the selective catalytic reducer 3 or not is judged, and if the white crystal blocks are large, the selective catalytic reducer 3 is considered to have crystallization faults.

Referring to fig. 3, the present embodiment also provides an aftertreatment structure including a particulate matter trap 1, a selective catalytic reduction device 3, a connecting cylinder 5, and a sealing member 7, wherein the selective catalytic reduction device 3 is communicated with the particulate matter trap 1 through an exhaust pipe 2; the exhaust pipe 2 is provided with an inspection opening 20; a detection channel 50 penetrating through the connecting cylinder 5 is formed in the connecting cylinder 5, and the connecting cylinder 5 is arranged on the inspection opening 20 so that the detection channel 50 is communicated with the exhaust pipe 2; the seal 7 is connected to the connector barrel 5 to close off the detection channel 50. When the vehicle is normal and does not need to be repaired, the sealing member 7 is connected with the connecting cylinder 5 to block the detection passage 50.

Preferably, the post-processing arrangement further comprises a detection device 4, the detection device 4 and the seal 7 being alternatively connected to the connector barrel 5. When the vehicle has poor economy or insufficient power and the like, the problem that the exhaust back pressure of the engine is high is inferred, the detection device 4 is connected with the connecting cylinder 5, and the detection device 4 extends into the detection channel 50 to detect whether the selective catalytic reduction device 3 has crystal blockage faults or not.

In the description of the present application, it should be noted that the terms "upper", "lower", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are only for convenience in describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present application. Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

It is noted that, in the present application, relational terms such as "first" and "second", and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The above description is merely exemplary of the present application and is presented to enable those skilled in the art to understand and practice the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.