CN113803144A

CN113803144A - Aftertreatment hydrocarbon coverage judgment method and aftertreatment system

Info

Publication number: CN113803144A
Application number: CN202111081714.6A
Authority: CN
Inventors: 赵德财; 魏京; 孙善良
Original assignee: Weichai Power Co Ltd
Current assignee: Weichai Power Co Ltd
Priority date: 2021-09-15
Filing date: 2021-09-15
Publication date: 2021-12-17

Abstract

The invention belongs to the technical field of engines, and provides a post-treatment hydrocarbon coverage judging method and a post-treatment hydrocarbon coverage judging system, wherein the post-treatment hydrocarbon coverage judging method comprises the following steps: acquiring an exhaust flow value, an environment temperature value, an intake temperature value, a first differential pressure value at the front end and the rear end of a DOC (diesel particulate filter), a second differential pressure value at the front end and the rear end of a DPF, a first upstream temperature value of the DOC and a second upstream temperature value of the DPF; judging whether the DOC and the DPF are covered by hydrocarbon according to the obtained value; and controlling the aftertreatment system to remove the hydrocarbon coating in a high-temperature regeneration mode according to the occurrence of the hydrocarbon coating of the DOC and the DPF. The aftertreatment hydrocarbon coverage judgment method provided by the invention realizes the judgment of aftertreatment hydrocarbon coverage from two aspects of DOC and DPF; key factors such as temperature and pressure difference change are considered, and whether hydrocarbon coverage exists can be accurately judged; after the hydrocarbon covering is identified, hydrocarbon elimination is carried out in a high-temperature regeneration mode, and the economy and the safety of the vehicle are guaranteed.

Description

Aftertreatment hydrocarbon coverage judgment method and aftertreatment system

Technical Field

The invention belongs to the technical field of engines, particularly relates to a post-treatment hydrocarbon coverage judgment method, and further relates to a post-treatment system.

Background

This section provides background information related to the present disclosure only and is not necessarily prior art.

In a cold environment, the air inlet temperature of a diesel engine is low, the combustion temperature in a cylinder is lower than that in a normal state, so that the combustion of diesel oil is incomplete, partial hydrocarbon is not fully combusted and is discharged from the cylinder, the hydrocarbon can be adhered to a DOC (oxidation catalytic converter) and a DPF (diesel particulate filter), when the adhesion amount of the hydrocarbon reaches a certain degree, the hydrocarbon can be subjected to oxidation reaction when the exhaust temperature is higher, and particularly in a regeneration mode, the exhaust temperature can be abnormally increased, so that certain harm is caused to the aftertreatment; meanwhile, the carbon hydrogen is attached to the DPF, so that the pressure difference of the DPF is increased, the exhaust back pressure is increased, the accuracy of a carbon loading model of the DPF is affected, and the fuel consumption of a vehicle is increased due to the excessive back pressure.

Disclosure of Invention

The invention aims to at least solve the problem that hydrocarbon coverage of an engine aftertreatment system influences the safety and the economy of a vehicle in the prior art, and the aim is realized by the following technical scheme:

the first aspect of the invention provides a method for judging after-treatment hydrocarbon coverage, which comprises the following steps:

acquiring an exhaust flow value, an environment temperature value, an intake temperature value, a first differential pressure value at the front end and the rear end of a DOC (diesel particulate filter), a second differential pressure value at the front end and the rear end of a DPF, a first upstream temperature value of the DOC and a second upstream temperature value of the DPF;

judging whether the DOC and the DPF are covered by hydrocarbon or not according to the exhaust flow value, the environment temperature value, the intake temperature value, the first differential pressure value, the second differential pressure value, the first upstream temperature value and the second upstream temperature value;

and controlling an aftertreatment system to remove the hydrocarbon coating in a high-temperature regeneration mode according to the DOC and the DPF.

The aftertreatment hydrocarbon coverage judgment method provided by the invention realizes the judgment of aftertreatment hydrocarbon coverage from two aspects of DOC and DPF; key factors such as temperature and pressure difference change are considered, and whether hydrocarbon coverage exists can be accurately judged; after the hydrocarbon covering is identified, hydrocarbon elimination is carried out in a high-temperature regeneration mode, and the economy and the safety of the vehicle are guaranteed.

In addition, the post-processing hydrocarbon coverage judging method can also have the following additional technical characteristics:

in some embodiments of the present invention, before the determining whether the DOC and the DPF are covered with hydrocarbons according to the exhaust gas flow rate value, the ambient temperature value, the intake air temperature value, the first differential pressure value, the second differential pressure value, the first upstream temperature value, and the second upstream temperature value, further includes:

judging whether the environment temperature value is smaller than a preset environment temperature value or not, and judging whether the air inlet temperature value is smaller than a preset air inlet temperature value or not;

and carrying out the next step according to the condition that the environment temperature value is smaller than the preset environment temperature value and the air inlet temperature value is smaller than the preset air inlet temperature value.

In some embodiments of the present invention, the determining whether the DOC and the DPF are covered with hydrocarbons according to the exhaust gas flow rate value, the ambient temperature value, the intake air temperature value, the first differential pressure value, the second differential pressure value, the first upstream temperature value, and the second upstream temperature value includes:

establishing a relation table of the exhaust flow value and a first preset differential pressure value;

judging whether the first differential pressure value is larger than a first preset differential pressure value corresponding to the exhaust flow value under the current working condition of the engine or not;

judging whether the difference value between the first differential pressure value and the first preset differential pressure value is greater than a first preset deviation value or not according to the fact that the first differential pressure value is greater than the first preset differential pressure value;

judging whether the duration value is greater than a first preset time threshold value or not according to the fact that the difference value between the first differential pressure value and the first preset differential pressure value is greater than the first preset deviation value;

and judging that the DOC is covered by hydrocarbon according to the condition that the duration value is greater than the first preset time threshold value.

In some embodiments of the present invention, the determining whether the DOC and the DPF are covered with hydrocarbons according to the exhaust gas flow rate value, the ambient temperature value, the first differential pressure value, the second differential pressure value, the first upstream temperature value, and the second upstream temperature value includes:

establishing a second relation table of the carbon loading amount of the DPF, the exhaust flow value and a second preset differential pressure value;

calculating the carbon carrying amount of the DPF according to the current working condition of the engine;

judging whether the second differential pressure value is larger than a second preset differential pressure value corresponding to the exhaust flow value and the carbon carrying quantity of the DPF under the current working condition of the engine or not;

judging whether the difference value between the second differential pressure value and the second preset differential pressure value is greater than a second preset deviation value or not according to the fact that the second differential pressure value is greater than the second preset differential pressure value;

judging whether the duration value is greater than a second preset time threshold value or not according to the fact that the difference value between the second differential pressure value and the second preset differential pressure value is greater than the second preset deviation value;

and judging that the DPF is covered by the hydrocarbon according to the condition that the duration value is greater than the second preset time threshold value.

In some embodiments of the present invention, before the determining whether the DOC and the DPF are covered by hydrocarbons according to the exhaust gas flow rate value, the ambient temperature value, the first differential pressure value, the second differential pressure value, the first upstream temperature value and the second upstream temperature value, further includes:

acquiring the fuel injection quantity and the torque value of the engine;

judging whether the first upstream temperature value is greater than a first preset temperature threshold and less than a second preset temperature threshold, judging whether the fuel injection quantity is greater than a first preset fuel injection quantity threshold and less than a second preset fuel injection quantity threshold, and judging whether the torque value is greater than 0;

and carrying out the next step according to the result that the first upstream temperature value is greater than the first preset temperature threshold and less than the second preset temperature threshold, the fuel injection quantity is greater than the first preset fuel injection quantity threshold and less than the second preset fuel injection quantity threshold, and the torque value is greater than 0.

judging whether the difference value between the first average value of the first upstream temperature value and the second average value of the second upstream temperature value is greater than a preset difference value or not within a third preset time threshold value;

judging whether the third preset time threshold is greater than a preset time set value or not according to the fact that the difference value between the first average value and the second average value is greater than the preset difference value;

and judging that the hydrocarbon coverage occurs according to the fact that the third preset time threshold is larger than the preset time set value.

In some embodiments of the invention, said controlling the aftertreatment system to remove the hydrocarbon coating in a high temperature regeneration manner based on said DOC and said DPF comprises:

acquiring a vehicle speed value;

judging whether the first upstream temperature value is greater than a third preset temperature threshold value, judging whether the exhaust flow value is greater than a preset exhaust flow threshold value, and judging whether the vehicle speed value is greater than a preset vehicle speed threshold value;

and judging that the exhaust flow value is greater than the preset exhaust flow threshold value according to the fact that the first upstream temperature value is greater than the third preset temperature threshold value, and controlling an engine to perform aftertreatment high-temperature regeneration when the vehicle speed value is greater than the preset vehicle speed threshold value.

In some embodiments of the present invention, the controlling the engine to perform the aftertreatment high temperature regeneration according to the first upstream temperature value being greater than the third preset temperature threshold, the exhaust flow value being greater than the preset exhaust flow threshold, and the vehicle speed value being greater than the preset vehicle speed threshold comprises:

controlling high temperature regeneration of the engine such that the second upstream temperature value remains within a preset temperature range;

and controlling the duration of the high-temperature regeneration to be a preset accumulated time value, wherein the preset accumulated time value is in direct proportion to the low-temperature ratio of the environmental temperature value.

A second aspect of the present invention provides an aftertreatment hydrocarbon coverage determination processing system for performing the aftertreatment hydrocarbon coverage determination method according to the first aspect of the present invention, including an engine, a DOC, a DPF for processing an exhaust gas of the engine, a DOC upstream temperature sensor for monitoring an upstream temperature of the DOC, a DOC differential pressure sensor for monitoring an upstream and downstream differential pressure of the DOC, a DPF upstream temperature sensor for monitoring an upstream and downstream temperature of the DOC, a DPF differential pressure sensor for monitoring an upstream and downstream temperature of the DPF, and an ECU connected to the engine, the DOC, the DPF, the DOC upstream temperature sensor, the DOC differential pressure sensor, the DPF upstream and downstream temperature sensor, the DOC differential pressure sensor, the DPF differential pressure sensor, the engine, the DOC, the DPF, the DOC upstream temperature sensor, the DPF differential pressure sensor, the ECU, and the DPF, respectively, The DPF upstream temperature sensor and the DPF differential pressure sensor are electrically connected.

The post-treatment hydrocarbon coverage judging and processing system provided by the second aspect of the invention has the same beneficial effects as the post-treatment hydrocarbon coverage judging and processing method provided by the first aspect of the invention, and the details are not repeated herein.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like parts are designated by like reference numerals throughout the drawings. In the drawings:

FIG. 1 schematically illustrates a schematic structural diagram of an aftertreatment hydrocarbon coverage determination system according to an embodiment of the invention;

FIG. 2 schematically shows a flow diagram of an aftertreatment hydrocarbon coverage determination method according to an embodiment of the invention.

The reference symbols in the drawings denote the following:

10: ECU, 11: DOC, 12: DPF, 13: SCR, 14: DOC upstream temperature sensor, 15: DOC differential pressure sensor, 16: DPF upstream temperature sensor, 17: DPF differential pressure sensor, 18: an SCR upstream temperature sensor.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

It is to be understood that the terminology used herein is for the purpose of describing particular example embodiments only, and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," "including," and "having" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order described or illustrated, unless specifically identified as an order of performance. It should also be understood that additional or alternative steps may be used.

Although the terms, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as "second" and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, an element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

For convenience of description, spatially relative terms, such as "inner", "outer", "inner", "side", "lower", "below", "upper", "above", and the like, may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. Such spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" or "over" the other elements or features. Thus, the example term "below … …" can include both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

As shown in fig. 1 and 2, a first aspect of the present invention provides a method for determining a hydrocarbon cover after treatment, including:

and controlling the aftertreatment system to remove the hydrocarbon coating in a high-temperature regeneration mode according to the occurrence of the hydrocarbon coating of the DOC and the DPF.

It can be understood that the exhaust flow value, the ambient temperature value, the intake temperature value, the first differential pressure value between the front end and the rear end of the DOC and the second differential pressure value between the front end and the rear end of the DPF, the first upstream temperature value of the DOC and the second upstream temperature value of the DPF can be obtained by monitoring a temperature sensor and a pressure sensor of the engine. Comparing the exhaust flow value and the first differential pressure value with a DOC differential pressure and exhaust flow relation table of uncovered hydrocarbon obtained by a test to judge whether the DOC is covered by the hydrocarbon or not; and in the same way, the exhaust flow value and the second differential pressure value can be compared with a relation table of DPF pressure difference and exhaust flow of uncovered hydrocarbon obtained by a test to judge whether the DPF is covered by the hydrocarbon or not.

The DOC is positioned in front of the DPF in the aftertreatment system, namely engine exhaust firstly passes through the DOC and then passes through the DPF, so that when no hydrocarbon is covered in the DOC, the DOC is influenced by energy loss, and the first upstream temperature value of the DOC is usually larger than the second upstream temperature value of the DPF; however, when there is coverage of hydrocarbon in the DOC, when the first upstream temperature value is greater than a set value (e.g. 250 ℃), the covered hydrocarbon in the DOC is oxidized, and releases a certain amount of heat, which causes the upstream temperature of the DPF to increase, i.e. the second upstream temperature is greater than the first upstream temperature value. Whether hydrocarbon coverage occurs in the aftertreatment can be judged by monitoring the second upstream temperature and the first upstream temperature value.

In some embodiments of the present invention, before determining whether the DOC and the DPF are covered by hydrocarbons according to the exhaust gas flow rate value, the ambient temperature value, the intake air temperature value, the first differential pressure value, the second differential pressure value, the first upstream temperature value and the second upstream temperature value, further includes:

judging whether the environmental temperature value is smaller than a preset environmental temperature value or not, and judging whether the intake air temperature value is smaller than a preset intake air temperature value or not;

and performing the next step according to the result that the environment temperature value is smaller than the preset environment temperature value and the air inlet temperature value is smaller than the preset air inlet temperature value.

In some embodiments of the present invention, determining whether the DOC and the DPF are covered with hydrocarbons according to the exhaust flow rate value, the ambient temperature value, the intake temperature value, the first differential pressure value, the second differential pressure value, the first upstream temperature value, and the second upstream temperature value includes:

judging whether the difference between the first differential pressure value and the first preset differential pressure value is greater than a first preset deviation value or not according to the fact that the first differential pressure value is greater than the first preset differential pressure value;

judging whether the duration value is greater than a first preset time threshold value or not according to the fact that the difference between the first differential pressure value and the first preset differential pressure value is greater than a first preset deviation value;

and judging that the DOC is covered by hydrocarbon according to the condition that the duration value is greater than a first preset time threshold value.

It should be noted that, differential pressure sensors are added at the front end and the rear end of the DOC to monitor the differential pressure at the front end and the rear end of the DOC, and when no hydrocarbon coverage is normally generated, the differential pressure at the two ends is smaller; when a certain amount of hydrocarbon is covered in the DOC, a certain pressure difference is formed between the front end and the rear end, and the pressure difference is related to the coverage of the hydrocarbon and the operation condition; the pressure difference between the front and the rear of the DOC without the whole vehicle coverage can be obtained through tests, and the assumption is as shown in the following table; the pressure difference corresponding to other exhaust flow can be obtained by a linear interpolation method.

TABLE 2 DOC differential pressure based on exhaust flow

x (exhaust gas flow rate): kg/h	300	500	700	900
					z (DOC differential pressure): hpa	3.5	5	7	8

If the measured DOC differential pressure is larger than the differential pressure range set by the upper table under a certain exhaust gas flow, the deviation exceeds the set deviation threshold value, and the duration exceeds the set time threshold value, a certain amount of hydrocarbon coverage in the DOC is considered.

In some embodiments of the present invention, determining whether the DOC and the DPF are covered with hydrocarbons according to the exhaust flow rate value, the ambient temperature value, the first differential pressure value, the second differential pressure value, the first upstream temperature value, and the second upstream temperature value includes:

judging whether the difference between the second differential pressure value and the second preset differential pressure value is greater than a second preset deviation value or not according to the fact that the second differential pressure value is greater than the second preset differential pressure value;

judging whether the duration value is greater than a second preset time threshold value or not according to the fact that the difference between the second differential pressure value and the second preset differential pressure value is greater than a second preset deviation value;

and judging that the DPF is covered by the hydrocarbon according to the condition that the duration value is greater than a second preset time threshold value.

It should be noted that, when the hydrocarbon covers the DPF, the pressure difference of the DPF is also increased compared with the normal condition, and in the working condition that the reliability of the pressure difference of the DPF is high, pressure difference sensors are added to the front end and the rear end of the DOC through the pressure difference of the DPF to monitor the pressure difference of the front end and the rear end of the DOC, and when the hydrocarbon does not cover normally, the pressure difference of the two ends is small; when a certain amount of hydrocarbon is covered in the DOC, a certain pressure difference is formed between the front end and the rear end, and the pressure difference is related to the coverage of the hydrocarbon and the operation condition;

under the normal condition without hydrocarbon coverage, the carbon deposition of the DPF has a certain rule, namely the ECU calculates the carbon loading capacity of the DPF according to the current working condition, and a DPF pressure difference in a certain range is generated corresponding to the carbon loading capacity, as shown in the following table 2, the abscissa is the carbon loading capacity root _ m, and the ordinate is the exhaust flow rate exh _ m; after the hydrocarbon is covered, the pressure difference of the DPF can be increased abnormally, and the pressure difference before and after the DPF without the whole automobile covering can be obtained through tests, and the following table is assumed; the pressure difference corresponding to other exhaust flow can be obtained by a linear interpolation method.

TABLE 2 DPF pressure differential distribution without hydrocarbon coverage

If the measured DPF differential pressure is greater than the differential pressure range set forth above at a certain exhaust gas flow rate, the deviation exceeds a set deviation threshold, and the duration exceeds a set time threshold, then it is deemed that there is some coverage of the DPF with hydrocarbons.

In some embodiments of the present invention, before determining whether the DOC and the DPF are covered by hydrocarbons according to the exhaust gas flow rate value, the ambient temperature value, the first differential pressure value, the second differential pressure value, the first upstream temperature value and the second upstream temperature value, further includes:

acquiring the fuel injection quantity and the torque value of the engine;

judging whether the first upstream temperature value is greater than a first preset temperature threshold and less than a second preset temperature threshold, judging whether the fuel injection quantity is greater than the first preset fuel injection quantity threshold and less than the second preset fuel injection quantity threshold, and judging whether the torque value is greater than 0 (excluding a drag-over working condition);

and according to the result that the first upstream temperature value is greater than a first preset temperature threshold and less than a second preset temperature threshold, judging that the fuel injection quantity is greater than the first preset fuel injection quantity threshold and less than the second preset fuel injection quantity threshold, and judging that the torque value is greater than 0 to perform the next step.

judging whether a third preset time threshold is greater than a preset time set value or not according to the fact that the difference value between the first average value and the second average value is greater than a preset difference value;

and judging that the hydrocarbon covering occurs according to the fact that the third preset time threshold is larger than the preset time set value.

It should be noted that, the DOC is located in front of the DPF in the aftertreatment system, that is, the engine exhaust passes through the DOC first and then passes through the DPF, so that when no hydrocarbon is covered in the DOC, the DOC is affected by energy loss, and the first upstream temperature is usually higher than the second upstream temperature; however, when the DOC has a hydrocarbon coating, when the first upstream temperature of the DOC is higher than a set value (e.g. 250 ℃), the hydrocarbon coating in the DOC is oxidized and releases a certain amount of heat, which causes the upstream temperature of the DPF to increase, i.e. the second upstream temperature is higher than the first upstream temperature.

In some embodiments of the invention, controlling the aftertreatment system to purge hydrocarbon overlap in a high temperature regeneration manner based on the DOC and DPF occurrence of hydrocarbon overlap comprises:

acquiring a vehicle speed value;

and according to the fact that the first upstream temperature value is larger than a third preset temperature threshold value, judging that the exhaust flow value is larger than a preset exhaust flow threshold value, and controlling the engine to carry out aftertreatment high-temperature regeneration when the vehicle speed value is larger than a preset vehicle speed threshold value.

In some embodiments of the present invention, determining that the exhaust flow value is greater than the preset exhaust flow threshold value and the vehicle speed value is greater than the preset vehicle speed threshold value according to the first upstream temperature value being greater than the third preset temperature threshold value, and controlling the engine to perform the aftertreatment high temperature regeneration comprises:

controlling high-temperature regeneration of the engine, wherein the regeneration is realized by conventional modes such as post-injection in an engine cylinder, air intake throttling valve and the like, so that a second upstream temperature value is kept in a preset temperature range;

and controlling the duration of the high-temperature regeneration to be a preset accumulated time value, wherein the preset accumulated time value is in direct proportion to the preset low-temperature value of the environmental temperature value.

Specifically, the regeneration accumulation time should be set, for example, 20min, and the effective time can be calculated when the second upstream temperature of the DPF reaches a certain range, and the effect of removing hydrocarbons in this temperature range is considered to be good. In order to ensure good regeneration effect, the set regeneration time is corrected according to the ratio of the preset low temperature value, namely, the more the ratio of the preset low temperature value is, the longer the regeneration time is. And taking the environment temperature less than 5 ℃ as a preset low temperature value.

TABLE 3 temperature-based regeneration time correction

x (lower ambient temperature ratio): is based on	30％	40％	50％	60％	70％
						z (regeneration time correction coefficient):	1	1.1	1.2	1.3	1.4

and judging whether the DOC and the DPF are covered by hydrocarbon according to the pressure difference, judging whether the DOC and/or the DPF are covered by hydrocarbon according to the exhaust temperature, and controlling the aftertreatment system to remove the hydrocarbon coverage in a high-temperature regeneration mode.

A second aspect of the present invention provides an aftertreatment hydrocarbon coverage determination processing system for performing the aftertreatment hydrocarbon coverage determination method according to the first aspect of the present invention, including an engine, a DOC11, a DPF12, a DOC upstream temperature sensor 14, a DOC differential pressure sensor 15, a DPF upstream temperature sensor 16, a DPF differential pressure sensor 17, and an ECU10, the DOC11 and the DPF12 being used for processing exhaust gas of the engine, the DPF12 being connected downstream of the DOC11, the DPF12 being connected downstream of the SCR13, the DOC upstream temperature sensor 14 being used for monitoring upstream temperature of the DOC11, the DOC differential pressure sensor 15 being used for monitoring upstream and downstream differential pressure of the DOC11, the DPF upstream temperature sensor 16 being used for monitoring upstream temperature of the DPF12, the DPF differential pressure sensor 17 being used for monitoring upstream and downstream differential pressure of the DPF12, the ECU10 is electrically connected to the engine, the DOC11, the DPF12, the DOC upstream temperature sensor 14, the DOC differential pressure sensor 15, the DPF upstream temperature sensor 16, and the DPF differential pressure sensor 17, respectively.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are also included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims

1. A method for determining hydrocarbon coverage after treatment, comprising:

2. The aftertreatment hydrocarbon placement determination method according to claim 1, wherein before determining whether hydrocarbon placement of the DOC and the DPF occurs according to the exhaust flow rate value, the ambient temperature value, the intake air temperature value, the first differential pressure value, the second differential pressure value, the first upstream temperature value, and the second upstream temperature value, the method further comprises:

3. The aftertreatment hydrocarbon placement determination method according to claim 1, wherein the determining whether the DOC and the DPF are hydrocarbon placed in hydrocarbon placement based on the exhaust flow rate value, the ambient temperature value, the intake temperature value, the first differential pressure value, the second differential pressure value, the first upstream temperature value, and the second upstream temperature value includes:

4. The aftertreatment hydrocarbon placement determination method according to claim 1, wherein the determining whether the DOC and the DPF are hydrocarbon placed in the hydrocarbon placement state based on the exhaust flow rate value, the ambient temperature value, the first differential pressure value, the second differential pressure value, the first upstream temperature value, and the second upstream temperature value includes:

5. The aftertreatment hydrocarbon placement determination method according to claim 1, wherein before determining whether hydrocarbon placement of the DOC and the DPF occurs according to the exhaust flow rate value, the ambient temperature value, the first differential pressure value, the second differential pressure value, the first upstream temperature value, and the second upstream temperature value, further comprises:

acquiring the fuel injection quantity and the torque value of the engine;

6. The aftertreatment hydrocarbon placement determination method according to claim 1, wherein the determining whether the DOC and the DPF are hydrocarbon placed in the hydrocarbon placement state based on the exhaust flow rate value, the ambient temperature value, the first differential pressure value, the second differential pressure value, the first upstream temperature value, and the second upstream temperature value includes:

7. The aftertreatment hydrocarbon coverage determination method according to claim 1, wherein the controlling an aftertreatment system to remove the hydrocarbon coverage in a high temperature regeneration manner according to the occurrence of the hydrocarbon coverage of the DOC and the DPF comprises:

acquiring a vehicle speed value;

and controlling an engine to carry out aftertreatment high-temperature regeneration according to the condition that the first upstream temperature value is greater than the third preset temperature threshold, the exhaust flow value is greater than the preset exhaust flow threshold, and the vehicle speed value is greater than the preset vehicle speed threshold.

8. The aftertreatment hydrocarbon cover determination method according to claim 7, wherein the determining that the exhaust flow value is greater than the preset exhaust flow threshold based on the first upstream temperature value being greater than the third preset temperature threshold, and the vehicle speed value being greater than the preset vehicle speed threshold, controlling an engine for aftertreatment high temperature regeneration comprises:

and controlling the duration of the high-temperature regeneration to be a preset accumulated time value, wherein the preset accumulated time value is in direct proportion to the preset low-temperature value of the environment temperature value.

9. An aftertreatment system for performing the aftertreatment hydrocarbon coverage determination method of any one of claims 1 to 8, it is characterized by comprising an engine, a DOC, a DPF, a DOC upstream temperature sensor, a DOC differential pressure sensor, a DPF upstream temperature sensor, a DPF differential pressure sensor and an ECU, the DOC and the DPF are used for treating exhaust gas of the engine, the DPF is connected with the downstream of the DOC, the DOC upstream temperature sensor is used for monitoring the upstream temperature of the DOC, the DOC differential pressure sensor is used for monitoring the upstream and downstream differential pressure of the DOC, the DPF upstream temperature sensor is used for monitoring the upstream temperature of the DPF, the DPF differential pressure sensor is used for monitoring the upstream and downstream differential pressure of the DPF, the ECU is electrically connected to the engine, the DOC, the DPF, the DOC upstream temperature sensor, the DOC differential pressure sensor, the DPF upstream temperature sensor, and the DPF differential pressure sensor, respectively.