CN210977650U

CN210977650U - Device for reducing exhaust back pressure of engine after DPF blockage in post-treatment of tractor

Info

Publication number: CN210977650U
Application number: CN201921988428.6U
Authority: CN
Inventors: 文武红; 王秀雷; 于春杰; 张伟刚
Original assignee: Tianjin Lovol Engines Co Ltd
Current assignee: Tianjin Lovol Engines Co Ltd
Priority date: 2019-11-20
Filing date: 2019-11-20
Publication date: 2020-07-10
Anticipated expiration: 2029-11-20

Abstract

The utility model relates to a device that reduces engine exhaust backpressure after tractor aftertreatment DPF blocks up belongs to tractor technical field, its characterized in that: the pipeline before the DPF is provided with an exhaust port before the DPF, the pipeline before the SCR is provided with an exhaust port before the SCR, the exhaust port before the DPF and the exhaust port before the SCR are communicated through an exhaust pipeline, the exhaust pipeline is provided with a pressure regulating valve, the exhaust pipeline is connected with a bypass provided with a pressure difference sensor, a measuring pipeline provided with the pressure difference sensor is connected behind the DPF of the post-processing assembly, and the calibers of the exhaust port before the DPF and the exhaust port before the SCR are the same. Through adopting above-mentioned technical scheme, this device that reduces engine exhaust back pressure after tractor aftertreatment DPF blocks up aims at solving when four aftertreatment assembly DPF blocks up in non-road state, avoids causing the injury to the engine.

Description

Device for reducing exhaust back pressure of engine after DPF blockage in post-treatment of tractor

Technical Field

The utility model belongs to the technical field of the tractor, concretely relates to reduce device of engine exhaust backpressure after tractor aftertreatment DPF blocks up.

Background

In order to adapt to the non-road state four-emission regulation, a tractor needs to be additionally provided with an aftertreatment system to reduce the emission of an engine, the aftertreatment scheme adopted is DOC + DPF + SCR, and the arrangement form is a straight type (or a straight-line type); the post-treatment assembly of the tractor, DPF assembly are located between DOC and SCR assembly, bolted connection, the straight-line shape. The main function of the DPF is to filter particulate matters in the tail gas of the diesel engine, so that the emission of the particulate matters of the diesel engine meets the requirement. In addition to the accumulated particulates, a portion of the particulates are consumed during passive regeneration. During the process of filtering particulate matters of the DPF, the exhaust back pressure of an engine can be continuously increased along with the accumulation of more and more particulate matters. At a certain carbon loading, equilibrium is reached, at which point the exhaust back pressure reaches a certain pressure without changing. However, as the usage time increases, or other boundary conditions change, active regeneration is required to burn off the accumulated carbon. But when a blockage alarm occurs, if the engine exhaust back pressure is high, the performance of the engine, such as dynamic performance, economical efficiency and the like, is affected. Therefore, certain measures are taken to ensure that the performance of the working engine is not influenced when the DPF is blocked under the condition of not changing the original designed aftertreatment structure.

The existing post-processing assembly structurally mainly inputs signals to a controller through a differential pressure sensor to judge whether the DPF is blocked or not, and two pipelines (a DPF front pipeline and a DPF rear pipeline) which are connected with the differential pressure sensor are arranged in front of and behind the DPF. If clogging occurs, the performance of the engine is reduced, affecting the operation of the agricultural machine, especially when the agricultural machine is operating. Therefore, it is necessary to improve the post-processing assembly so that the performance of the engine is not affected during the operation of the agricultural machine when the DPF is clogged, and to handle the malfunction after the operation is completed.

At present, post-treatment DPF assemblies of non-road countries are all provided with pressure difference sensors, and the blockage problem of the DPF is realized by identifying the pressure difference sensors and a carbon loading model through complex control logic. When the agricultural machine works, once the DPF is blocked and gives an alarm, the machine is stopped to carry out parking regeneration, and the machine needs to be driven to a safe place.

The prior art has the following disadvantages:

by adopting the prior art, when the alarm occurs in the operation process, the agricultural machine at the moment can be positioned in the operation land, so that the power of the engine is reduced, and the normal operation is influenced. If the DPF becomes severely plugged, it can cause damage to the engine. This is currently difficult to achieve accurately by the assembly structure and corresponding control logic as shown in fig. 1. In addition, the complicated control logic requires a long test period, and the test cost is increased.

SUMMERY OF THE UTILITY MODEL

The utility model discloses a solve the technical problem who exists among the known technology, provide a device that reduces engine exhaust backpressure after tractor aftertreatment DPF blocks up, when this device that reduces engine exhaust backpressure after tractor aftertreatment DPF blocks up aims at solving four aftertreatment assembly DPF of non-road state and blocks up, avoid causing the injury to the engine.

The utility model aims at providing a device that reduces engine exhaust backpressure after tractor aftertreatment DPF blocks up sets up gas vent (1) before the DPF on the pipeline before the DPF, sets up gas vent (4) before SCR on the pipeline before SCR, through exhaust pipe (6) intercommunication between gas vent (1) before the DPF and gas vent (4) before SCR install pressure regulating valve (3) on exhaust pipe (6) be connected with bypass (2) of installing differential pressure sensor on exhaust pipe (6), be connected with installation differential pressure sensor behind aftertreatment assembly DPF and measure the pipeline, gas vent (1) before the DPF is the same with gas vent (4) bore before SCR.

Further: the pressure regulating valve (3) is a mechanical regulating valve.

Further: the pressure regulating valve (3) is an electric control type regulating valve.

The utility model has the advantages and positive effects that:

the utility model discloses the back pressure of exhaust pipe risees when well pipeline of taking pressure regulating valve who connects DPF entry and SCR entry can effectually prevent DPF jam to reduce the harm to the engine. Meanwhile, if serious blockage occurs in the operation process, the engine can normally work and cannot be flamed out. The method is an effective auxiliary measure for dealing with DPF blockage.

The utility model is improved on the original basis, the original DOC + DPF + SCR in-line type structure is not greatly changed, and the development time is saved; in addition, the device can reduce the workload of the test and shorten the test period.

Drawings

FIG. 1 is a first state diagram of the preferred embodiment of the present invention;

FIG. 2 is a second state diagram of the preferred embodiment of the present invention;

wherein: 1. an exhaust port in front of the DPF; 2. a pipeline connected with the differential pressure sensor; 3. a pressure regulating valve; 4. an exhaust port before SCR; 5. the front and rear pipeline intersections of the DPF are connected with a differential pressure sensor; 6. an exhaust line; 7. and installing a differential pressure sensor measuring pipeline.

Detailed Description

For further understanding of the contents, features and effects of the present invention, the following embodiments are exemplified and will be described in detail with reference to the accompanying drawings:

referring to fig. 1 to 2, a device for reducing exhaust back pressure of an engine after DPF clogging is post-treated by a tractor comprises two parts, the first part is a post-treatment assembly with exhaust ports in front of the DPF and the SCR, and the other part is a bypass pipeline (with a pressure regulating valve) connecting the front of the DPF and the front of the SCR. The bypass pipeline with the pressure regulating valve comprises a bypass 2 connected with a differential pressure sensor, an exhaust pipeline 6 and a pressure regulating valve 3; for the post-treatment assembly, two exhaust ports with the same diameter as that of a bypass pipeline are required to be opened on a pipeline in front of the DPF and a pipeline in front of the SCR, and the bypass pipeline is connected through a flange. In the figure, 1 is an exhaust port in front of a DPF, 7 is a measurement pipeline provided with a differential pressure sensor, namely a pipeline for connecting the differential pressure sensor behind the DPF of an original post-treatment assembly, and 4 is an exhaust port in front of an SCR. 5 is the front and back pipe mouth of DPF connected with the differential pressure sensor.

Working principle of the above preferred embodiment:

under normal operating conditions, the exhaust backpressure does not rise until the DPF is unplugged, and normal exhaust flow is shown by the arrows in FIG. 1 and does not pass through the bypass line. The pressure regulating valve 3 is closed at this time. The exhaust back pressure is measured by a differential pressure sensor. The pressure regulation can be a mechanical valve or an electric control valve; the mechanical valve is adopted, so that the cost is low, and the valve is simple and convenient; the opening time and the opening duration of the pressure regulating valve can be flexibly controlled by adopting electric control.

When the DPF is blocked, the exhaust back pressure rises, and if a mechanical pressure valve is adopted, when the set value of the pressure valve is exceeded, the pressure valve is opened; if an electrically controlled pressure valve is used, the timing and duration of the opening is determined according to the control logic. When the pressure regulating valve 3 is opened, the exhaust flows to a pipeline which enters a bypass pipeline 6 through the exhaust port 1, passes through the pressure regulating valve, then enters the SCR through the exhaust port 4, and finally is discharged to the atmosphere through the SCR assembly. The pressure regulating valve is open as shown in fig. 2. The preferred embodiment is to prevent the engine performance deterioration caused by the exhaust rising if the DPF is blocked during the operation of the tractor, so that the engine can be parked and regenerated or cleaned specially after the operation of a user is finished under the condition that the performance deterioration is not serious.

The utility model adds a pipeline with a pressure regulating valve for connecting the DPF inlet and the SCR inlet on the post-processing assembly to reduce the exhaust back pressure of the exhaust pipeline when the DPF is blocked; the pressure regulating valve is controlled in an electrically controlled manner or in a non-electrically controlled manner (mechanical valve). The electronic control mode can accurately control the opening time, the opening degree, the opening duration and the like of the pressure regulating valve to realize flexible control.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention in any way, and all the modifications and equivalents of the technical spirit of the present invention to any simple modifications of the above embodiments are within the scope of the technical solution of the present invention.

Claims

1. The utility model provides a device that reduces engine exhaust backpressure after tractor aftertreatment DPF blocks up which characterized in that: offer exhaust port (1) before DPF on the pipeline before DPF, offer exhaust port (4) before SCR on the pipeline before SCR, through exhaust pipe (6) intercommunication between exhaust port (1) before DPF and exhaust port (4) before SCR install pressure regulating valve (3) on exhaust pipe (6) be connected with bypass (2) of installing differential pressure sensor on exhaust pipe (6), be connected with installation differential pressure sensor behind the post-processing assembly DPF and measure pipeline (7), exhaust port (1) before DPF and exhaust port (4) bore before SCR are the same.

2. The device for reducing the exhaust back pressure of the engine after the DPF is blocked by the tractor according to claim 1, wherein: the pressure regulating valve (3) is a mechanical regulating valve.

3. The device for reducing the exhaust back pressure of the engine after the DPF is blocked by the tractor according to claim 1, wherein: the pressure regulating valve (3) is an electric control type regulating valve.