Exhaust control method and system for double engines

Abstract

The invention relates to the technical field of engine tail gas treatment, in particular to a double-engine exhaust control method and system, and the method comprises the steps that an engine performance model is constructed; working condition parameters of N engines are obtained; inputting the working condition parameters of N engines into the engine performance model to obtain tail gas emission of i pollutants; and determining a tail gas treatment strategy according to the tail gas emission amount of each pollutant. According to the engine performance model constructed by the method, the working condition parameters of the multiple engines can be obtained, parallel calculation is carried out on tail gas discharged by the multiple engines, the mass of various pollutants in the tail gas is rapidly calculated, and then the corresponding treatment modules of the tail gas treatment system are controlled according to the types of the pollutants. According to the exhaust control method, the tail gas treatment system can be controlled to conduct tail gas treatment on the multiple engines at the same time, and the tail gas treatment cost is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of engine exhaust treatment, and in particular to an exhaust control method and system for a dual engine. Background Art

[0002] In order to control automobile exhaust emissions, China has formulated the sixth stage of motor vehicle pollutant emission standards, which require that engine exhaust emissions must not exceed the pollutant emission limit standards. Engine exhaust pollutants mainly include nitrogen oxides, carbon monoxide, hydrocarbons and solid particles.

[0003] Therefore, in order to reduce the content of exhaust pollutants, it is necessary to install an exhaust treatment system in the exhaust system of the engine. The DPF, SCR, DOC and ASC modules in the exhaust treatment system can respectively treat different types of pollutants.

[0004] Special vehicles, such as sanitation vehicles and cranes, are generally equipped with two engines, one is the main engine that drives the vehicle, and the other is the auxiliary engine that drives the operation. Existing special vehicles also need to be equipped with two separate exhaust gas treatment systems to treat the exhaust gas of the two engines respectively.

[0005] When special vehicles are operating, the load on the main engine is low, which will lead to the following two problems:

[0006] (1) The exhaust temperature of the main engine is low, which causes the SCR to fail to reach the operating temperature and the exhaust gas treatment system cannot effectively filter nitrogen oxides.

[0007] (2) Incomplete engine combustion leads to an increase in carbon particles, and the exhaust temperature is too low, which makes it impossible for the carbon soot in the DPF to regenerate, eventually causing the DPF to be blocked.

[0008] In order to avoid the above-mentioned problems in the exhaust treatment system of special vehicles, the present application provides an exhaust control method and system for a dual engine. Summary of the invention

[0009] In order to overcome the problems existing in the related art, the first aspect of the present application provides an exhaust control method for a dual engine, comprising:

[0010] Constructing an engine performance model; the engine performance model is used to calculate the exhaust emissions of N engines under different operating conditions;

[0011] Obtain operating parameters of N engines;

[0012] Inputting the operating parameters of N engines into the engine performance model to obtain the tail gas emissions of i types of pollutants;

[0013] The exhaust gas treatment strategy is determined according to the exhaust gas emission of each pollutant; N is an integer greater than or equal to 2, and i is an integer greater than or equal to 1.

[0014] In one implementation, the engine performance model specifically includes:

[0015]

[0016] m i =k i ×Q mew

[0017] Among them, Q mew represents the exhaust gas flow rate of N engines, Q mew,n represents the exhaust gas flow rate of the nth engine, m i represents the exhaust emission of the i-th pollutant in the total exhaust emission, k i Represents the emission factor of the ith pollutant.

[0018] In one embodiment, determining the tail gas treatment strategy according to the tail gas emission of each pollutant includes:

[0019] Obtaining NOx emissions;

[0020] determining a urea injection amount according to the nitrogen oxide emission amount;

[0021] Control SCR to inject urea in the after-treatment pipeline.

[0022] In one embodiment, determining the tail gas treatment strategy according to the tail gas emission of each pollutant includes:

[0023] Obtain the pressure difference between the inlet and outlet sides of the DPF;

[0024] Determine whether the pressure difference is greater than or equal to a preset pressure threshold, if so, perform DPF regeneration; if not, continue to detect the pressure difference.

[0025] In one embodiment, the DPF regeneration specifically includes:

[0026] The carbon load of the DPF is calculated based on the pressure difference between the inlet and outlet sides of the DPF;

[0027] The exhaust temperature of the engine is controlled according to the carbon loading.

[0028] A second aspect of the present application provides an exhaust control system for a dual engine, which executes the steps of the exhaust control method described in the present application under the control of an electronic control unit;

[0029] The exhaust control system includes an after-treatment pipeline and N intake pipelines;

[0030] The N intake pipes are respectively connected to the exhaust gas outlets of the N engines, and the post-processing pipe is provided with an exhaust gas treatment unit and an exhaust gas detection unit, and the exhaust gas treatment unit and the exhaust gas detection unit are respectively connected to an electronic control unit for communication;

[0031] The exhaust gas detection unit is used to detect exhaust gas parameters and send them to the electronic control unit;

[0032] The tail gas treatment unit is used for tail gas treatment;

[0033] The electronic control unit is used to control the exhaust gas detection unit and the exhaust gas treatment unit.

[0034] In one embodiment, a one-way valve is provided at the air outlet of the air inlet pipe.

[0035] In one embodiment, the air intake duct is provided with a thermal insulation layer.

[0036] In one embodiment, the exhaust gas treatment unit includes a DOC module, a DPF module and an SCR module.

[0037] In one embodiment, the exhaust gas detection unit includes a differential pressure sensor and two nitrogen oxide sensors;

[0038] The differential pressure sensor is arranged at both ends of the DPF module to measure the back pressure of the DPF module;

[0039] The two nitrogen oxide sensors are respectively arranged at the air inlet and the air outlet of the post-treatment pipe, and the nitrogen oxide sensors are used to detect the nitrogen oxide concentration before and after the exhaust gas treatment.

[0040] The technical solution provided by this application may have the following beneficial effects:

[0041] The engine performance model constructed in this application can obtain the operating parameters of multiple engines, perform parallel calculations on the exhaust gases emitted by multiple engines, quickly calculate the mass of various pollutants in the exhaust gas, and then control the corresponding processing modules of the exhaust gas treatment system according to the type of pollutants. The exhaust control method of this application can control the exhaust gas treatment system to treat the exhaust gases of multiple engines at the same time, reducing the cost of exhaust gas treatment.

[0042] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The above and other objects, features and advantages of the present application will become more apparent through a more detailed description of exemplary embodiments of the present application in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the present application.

[0044] Figure 1 A schematic flow chart of an exhaust control method according to an embodiment of the present application;

[0045] Figure 2 This is a structural diagram of the exhaust control system shown in an embodiment of the present application. DETAILED DESCRIPTION

[0046] The preferred embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the preferred embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0047] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The singular forms of "a", "said" and "the" used in this application and the appended claims are also intended to include plural forms unless the context clearly indicates other meanings. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0048] It should be understood that although the terms "first", "second", "third", etc. may be used in this application to describe various information, this information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of this application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0049] Embodiment 1

[0050] Existing special vehicles are generally equipped with two separate exhaust gas treatment systems to treat the exhaust gas of the two engines respectively. This exhaust gas treatment method currently has two defects. The first is that the main engine load is low during operation, the exhaust temperature is low, which causes the SCR to fail to reach the operating temperature and the SCR to fail to reach the optimal operating temperature; the second is that the main engine combustion is not complete, resulting in an increase in carbon particles, which easily causes the DPF to be blocked.

[0051] An embodiment of the present application provides an exhaust control method, which is implemented through an exhaust gas treatment system of a special vehicle.

[0052] Different from the existing exhaust gas treatment system, the air intake of the exhaust gas treatment system of the embodiment of the present application is connected to the exhaust gas discharge ports of N engines, and the exhaust gas of the main engine and the auxiliary engine is treated by a set of exhaust gas treatment system.

[0053] The exhaust control method of the embodiment of the present application is as follows Figure 1 As shown, the following steps are included:

[0054] S1. Build engine performance model;

[0055] Specifically, the engine performance model is used to calculate the exhaust emissions of N engines under different operating conditions.

[0056] It can be understood that the engine performance model is a network model or a mathematical simulation model based on deep learning.

[0057] S2. Obtaining operating parameters of N engines;

[0058] S3, inputting the operating parameters of the N engines into the engine performance model to obtain the tail gas emissions of i types of pollutants;

[0059] S4. Determine an exhaust gas treatment strategy according to the exhaust gas emission of each pollutant; N is an integer greater than or equal to 2, and i is an integer greater than or equal to 1.

[0060] Specifically, in step S1, the engine performance model specifically includes:

[0061]

[0062] m i =k i ×Q mew

[0063] Among them, Q mew represents the exhaust gas flow rate of N engines, Q mew,n represents the exhaust gas flow rate of the nth engine, m i represents the exhaust emission of the i-th pollutant in the total exhaust emission, k i Represents the emission factor of the ith pollutant.

[0064] In the exhaust gas treatment system of the embodiment of the present application, it is equipped with DOC, DPF and SCR. Among them, DOC is used to convert carbon monoxide and hydrocarbons emitted by diesel engines into harmless carbon dioxide and water through catalytic oxidation reaction. DPF is used to capture particulate matter by filtering. SCR is used to inject urea to reduce nitrogen oxides.

[0065] Furthermore, step S4 specifically includes:

[0066] Obtaining NOx emissions;

[0067] determining a urea injection amount according to the nitrogen oxide emission amount;

[0068] Control SCR to inject urea in the after-treatment pipeline.

[0069] In order to ensure the filtering efficiency of DPF, it is necessary to monitor the carbon load of DPF in real time. If the carbon load of DPF reaches a preset threshold, DPF regeneration is performed.

[0070] Furthermore, step S4 specifically includes:

[0071] Obtain the pressure difference between the inlet and outlet sides of the DPF;

[0072] Determine whether the pressure difference is greater than or equal to a preset pressure threshold, if so, perform DPF regeneration; if not, continue to detect the pressure difference.

[0073] The carbon load of the DPF is calculated based on the pressure difference between the inlet and outlet sides of the DPF;

[0074] The exhaust temperature of the engine is controlled according to the carbon loading.

[0075] The engine performance model constructed in the embodiment of the present application can obtain the operating parameters of multiple engines, perform parallel calculations on the exhaust gases emitted by multiple engines, quickly calculate the mass of various pollutants in the exhaust gas, and then control the corresponding processing modules of the exhaust gas treatment system according to the type of pollutants. Therefore, the exhaust control method can control the exhaust gas treatment system to treat the exhaust gases of multiple engines at the same time, reducing the cost of exhaust gas treatment.

[0076] Embodiment 2

[0077] An embodiment of the present application provides an exhaust control system for a dual engine, which executes the steps of the exhaust control method described in the first embodiment under the control of an electronic control unit.

[0078] The exhaust control system shown in the embodiment of the present application is as follows Figure 2 As shown, it includes an after-treatment pipeline and N intake pipelines.

[0079] Specifically, the N intake pipes are respectively connected to the exhaust gas exhaust ports of the N engines, and the post-processing pipe is provided with an exhaust gas treatment unit and an exhaust gas detection unit, and the exhaust gas treatment unit and the exhaust gas detection unit are respectively communicatively connected to an electronic control unit.

[0080] The exhaust gas detection unit is used to detect exhaust gas parameters and send them to the electronic control unit; the exhaust gas treatment unit is used to perform exhaust gas treatment; and the electronic control unit is used to control the exhaust gas detection unit and the exhaust gas treatment unit.

[0081] In the driving mode, in order to prevent exhaust gas from flowing back between the intake pipes, the outlets of the intake pipes are respectively provided with one-way valves.

[0082] Since multiple engines share one exhaust gas treatment system, the length of the intake duct needs to be extended. In order to prevent the exhaust gas temperature from dropping, the intake duct is provided with a heat preservation layer.

[0083] Specifically, the exhaust gas treatment unit includes a DOC module, a DPF module and an SCR module.

[0084] Specifically, the exhaust gas detection unit includes a differential pressure sensor and two nitrogen oxide sensors. The differential pressure sensor is arranged at both ends of the DPF module to measure the back pressure of the DPF module; the two nitrogen oxide sensors are respectively arranged at the air inlet and the air outlet of the post-treatment pipeline, and the nitrogen oxide sensors are used to detect the nitrogen oxide concentration before and after the exhaust gas treatment.

[0085] The exhaust control system shown in the embodiment of the present application is connected to the exhaust ports of multiple engines through an intake pipe, and the exhaust gas is collected in a post-treatment pipeline for treatment, thereby reducing the number of exhaust gas treatment components and reducing equipment costs.

[0086] Regarding the device in the above embodiment, the specific way in which each module performs the operation has been described in detail in the embodiment of the method, and will not be elaborated here.

[0087] The scheme of the present application has been described in detail above with reference to the accompanying drawings. In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the relevant description of other embodiments. Those skilled in the art should also be aware that the actions and modules involved in the description are not necessarily required for the present application.

[0088] In addition, it can be understood that the steps in the method of the embodiment of the present application can be adjusted in order, combined and deleted according to actual needs, and the modules in the device of the embodiment of the present application can be combined, divided and deleted according to actual needs.

[0089] In addition, the method according to the present application may also be implemented as a computer program or a computer program product, which includes computer program code instructions for executing some or all of the steps in the above method of the present application.

[0090] Alternatively, the present application can also be implemented as a non-temporary machine-readable storage medium (or computer-readable storage medium, or machine-readable storage medium) on which executable code (or computer program, or computer instruction code) is stored. When the executable code (or computer program, or computer instruction code) is executed by a processor of an electronic device (or electronic device, server, etc.), the processor executes part or all of the steps of the above-mentioned method according to the present application.

[0091] Those skilled in the art will further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the application herein may be implemented as electronic hardware, computer software, or combinations of both.

[0092] The flow chart and block diagram in the accompanying drawings show the possible architecture, function and operation of the system and method according to multiple embodiments of the present application. In this regard, each square box in the flow chart or block diagram can represent a part of a module, a program segment or a code, and the part of the module, the program segment or the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the square box can also occur in a sequence different from that marked in the accompanying drawings. For example, two continuous square boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each square box in the block diagram and / or the flow chart, and the combination of the square boxes in the block diagram and / or the flow chart can be implemented with a dedicated hardware-based system that performs the specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0093] The embodiments of the present application have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein.

Claims

1. A dual-engine exhaust control method, characterized in that: include: Build engine performance models; The engine performance model is used to calculate the exhaust emissions of N engines under different operating conditions; Obtain operating parameters of N engines; Inputting the operating parameters of N engines into the engine performance model to obtain the tail gas emissions of i types of pollutants; Determining an exhaust gas treatment strategy based on the exhaust gas emission of each pollutant; N is an integer greater than or equal to 2, and i is an integer greater than or equal to 1.

2. The exhaust control method of a dual engine according to claim 1, characterized in that: The engine performance model specifically includes: m i =k i ×Q mew Among them, Q mew represents the exhaust gas flow rate of N engines, Q mew,n represents the exhaust gas flow rate of the nth engine, m i represents the exhaust emission of the i-th pollutant in the total exhaust emission, k i Represents the emission factor of the ith pollutant.

3. The exhaust control method of a dual engine according to claim 2, characterized in that: The tail gas treatment strategy is determined according to the tail gas emission of each pollutant, including: Obtaining NOx emissions; determining a urea injection amount according to the nitrogen oxide emission amount; Control SCR to inject urea in the after-treatment pipeline.

4. The exhaust control method of a dual engine according to claim 3, characterized in that: The tail gas treatment strategy is determined according to the tail gas emission of each pollutant, including: Obtain the pressure difference between the inlet and outlet sides of the DPF; Determine whether the pressure difference is greater than or equal to a preset pressure threshold, if so, perform DPF regeneration; if not, continue to detect the pressure difference.

5. The exhaust control method of a dual engine according to claim 4, characterized in that: The DPF regeneration specifically includes: The carbon load of the DPF is calculated based on the pressure difference between the inlet and outlet sides of the DPF; The exhaust temperature of the engine is controlled according to the carbon loading.

6. An exhaust control system for a dual engine, characterized in that: Executing the steps of the exhaust control method according to any one of claims 1 to 5 under the control of an electronic control unit; The exhaust control system includes an after-treatment pipeline and N intake pipelines; The N intake pipes are respectively connected to the exhaust gas outlets of the N engines, and the post-processing pipe is provided with an exhaust gas treatment unit and an exhaust gas detection unit, and the exhaust gas treatment unit and the exhaust gas detection unit are respectively connected to an electronic control unit for communication; The exhaust gas detection unit is used to detect exhaust gas parameters and send them to the electronic control unit; The tail gas treatment unit is used for tail gas treatment; The electronic control unit is used to control the exhaust gas detection unit and the exhaust gas treatment unit.

7. The exhaust control system of a dual engine according to claim 6, characterized in that: The air outlet of the air inlet pipe is provided with a one-way valve.

8. The exhaust control system of a dual engine according to claim 7, characterized in that: The air intake duct is provided with a heat insulation layer.

9. The exhaust control system of a dual engine according to claim 6, characterized in that: The exhaust gas treatment unit includes a DOC module, a DPF module and an SCR module.

10. The exhaust control system of a dual engine according to claim 9, characterized in that: The exhaust gas detection unit includes a differential pressure sensor and two nitrogen oxide sensors; The differential pressure sensor is arranged at both ends of the DPF module to measure the back pressure of the DPF module; The two nitrogen oxide sensors are respectively arranged at the air inlet and the air outlet of the post-treatment pipe, and the nitrogen oxide sensors are used to detect the nitrogen oxide concentration before and after the exhaust gas treatment.

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