Exhaust temperature control system and exhaust temperature control method of engine and vehicle

Abstract

According to the exhaust temperature control system, when first temperature information is larger than or equal to first preset temperature, the engine works in a first mode, a cylinder deactivation mechanism and a VGT supercharger work, and an EGR valve stops working; and the fuel oil pre-injection function and the fuel oil main injection function of the fuel oil injection mechanism are started, and the fuel oil post-injection function is stopped. And when the first temperature information is smaller than a first preset temperature, second temperature information of a second SCR is obtained, and when the second temperature information is smaller than a second preset temperature, the engine works in a second mode, the cylinder deactivation mechanism stops working, and the VGT supercharger and the EGR valve work. And the fuel oil pre-injection function, the fuel oil main injection function and the fuel oil rear injection function of the fuel oil injection mechanism are all started. Thus, in the first mode, fuel consumption of the engine can be improved, and in the second mode, rapid temperature rise is achieved, and generation of harmful emissions is reduced.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of engine technology, and in particular to an exhaust temperature control system, an exhaust temperature control method and a vehicle of an engine. Background Art

[0002] As public environmental awareness increases, vehicle emission regulations are becoming increasingly stringent. The EU officially adopted the Euro VII emission standard and heavy-duty vehicle CO2 emission standard in 2024. my country has implemented the National VI emission regulations in stages across the country, and the National VII emission has entered the pre-research stage. Commercial vehicles will face more stringent emission and fuel consumption regulations in the future.

[0003] Nitrogen oxides (NOx) are one of the main emissions from diesel engines. Two technical measures are mainly used to control NOx emissions: EGR (Exhaust Gas Recirculation) and SCR (Selective Catalytic Reduction). In order to meet future regulatory requirements, on the one hand, it is necessary to upgrade the technology of National VI diesel engines to more accurately control NOx emissions and reduce fuel consumption. On the other hand, it is necessary to adopt more efficient exhaust temperature thermal management technology to keep the post-processor in an efficient working range and improve conversion efficiency. Summary of the invention

[0004] The present invention provides an exhaust temperature control system, an exhaust temperature control method and a vehicle of an engine. When the first temperature information of a first SCR is greater than or equal to a first preset temperature, the engine is controlled to operate in a first operating mode to improve the fuel consumption of the engine during normal operation. When the first temperature information of the first SCR is less than the first preset temperature, the second temperature information of the second SCR is obtained, and when the second temperature information is less than the second preset temperature, the engine is controlled to operate in a second mode to quickly heat up a post-processing device to a normal operating temperature to reduce the generation of harmful emissions.

[0005] In a first aspect, an embodiment of the present invention provides an exhaust temperature control system of an engine, the engine comprising an engine body, a cylinder deactivation mechanism, a fuel injection mechanism, an EGR valve, and a VGT supercharger; the exhaust temperature control system comprises a monitoring control module and a post-processing device;

[0006] The aftertreatment device includes a first SCR far from the VGT supercharger and a second SCR close to the VGT supercharger;

[0007] The monitoring control module is electrically connected to the engine and the post-processing device, respectively, and is used to obtain first temperature information of the first SCR, and when the first temperature information is greater than or equal to a first preset temperature, sends a first control signal to the cylinder deactivation mechanism, the fuel injection mechanism, the EGR valve, and the VGT supercharger, so that the engine operates in a first mode. In the first mode, the cylinder deactivation mechanism and the VGT supercharger are in a working state, the EGR valve stops working, and the fuel pre-injection function and the fuel main injection function of the fuel injection mechanism are started, and the fuel post-injection function is disabled;

[0008] The monitoring and control module is also used to obtain second temperature information of the second SCR when the first temperature information is less than the first preset temperature, and to initiate a second control signal to the cylinder deactivation mechanism, the fuel injection mechanism, the EGR valve and the VGT supercharger when the second temperature information is less than the second preset temperature, so that the engine operates in a second mode. In the second mode, the cylinder deactivation mechanism stops working, the VGT supercharger and the EGR valve are in working state, and the fuel pre-injection function, the fuel main injection function and the fuel post-injection function of the fuel injection mechanism are all enabled; the first preset temperature is greater than the second preset temperature.

[0009] Optionally, the monitoring and control module is also used to obtain the oil temperature information of the engine body when the second temperature information is greater than or equal to the second preset temperature, and to control the engine to operate in the second mode when the oil temperature information is less than a third preset temperature, and to send a third control signal to the cylinder deactivation mechanism, the fuel injection mechanism, the EGR valve and the VGT supercharger when the oil temperature information is greater than or equal to the third preset temperature, so that the engine operates in a third mode. In the third mode, the cylinder deactivation mechanism, the VGT and the EGR valve are all in working condition, and the fuel pre-injection function and the fuel main injection function of the fuel injection mechanism are started, and the fuel post-injection function is disabled, wherein the third preset temperature is lower than the second preset temperature.

[0010] Optionally, in the first mode, the cylinder deactivation mechanism determines first cylinder deactivation information according to the rotation speed and load of the engine body and operates with the first cylinder deactivation information, wherein the first cylinder deactivation information includes a first cylinder deactivation area, a first cylinder deactivation number and a first cylinder deactivation combination;

[0011] In the third mode, the cylinder deactivation mechanism determines second cylinder deactivation information according to the rotation speed and load of the engine body and operates with the second cylinder deactivation information, where the second cylinder deactivation information includes a second cylinder deactivation area, a second cylinder deactivation number and a second cylinder deactivation combination.

[0012] Optionally, the second cylinder deactivation area is larger than the first cylinder deactivation area.

[0013] Optionally, when the VGT supercharger is in a working state, the opening information of the VGT supercharger is determined according to the rotation speed and load of the engine body;

[0014] The opening information of the VGT supercharger in the second mode is greater than the opening information of the VGT supercharger in the third mode, and the opening information of the VGT supercharger in the third mode is greater than the opening information of the VGT supercharger in the first mode.

[0015] Optionally, when the EGR valve is in a working state, the opening information of the EGR valve is determined according to the rotation speed and load of the engine body;

[0016] The opening information of the EGR valve in the second mode is greater than the opening information of the EGR valve in the third mode.

[0017] Optionally, the volume of the first SCR is T1, the volume of the second SCR is T2, and the first SCR and the second SCR satisfy: 1 / 4≤T2 / T1≤1 / 2.

[0018] Optionally, the monitoring control module includes a first temperature sensor, a second temperature sensor, a third temperature sensor, a fourth temperature sensor and an oil temperature sensor;

[0019] The first temperature sensor is disposed at an air outlet of the first SCR, and the second temperature sensor is disposed at an air inlet of the first SCR;

[0020] The third temperature sensor is disposed at the air outlet of the second SCR, and the fourth temperature sensor is disposed at the air inlet of the second SCR;

[0021] The monitoring and control module is further used to determine the first temperature information according to the temperature information of the first temperature sensor and the temperature information of the second temperature sensor, and to determine the second temperature information according to the temperature information of the third temperature sensor and the temperature information of the fourth temperature sensor;

[0022] The oil temperature sensor is arranged on the engine body.

[0023] In a second aspect, an embodiment of the present invention further provides an engine exhaust temperature control method, which is applied to the engine exhaust temperature control system according to any one of the first aspects, and the exhaust temperature control method includes:

[0024] Acquiring first temperature information of the first SCR;

[0025] and when the first temperature information is greater than or equal to a first preset temperature, sending a first control signal to the cylinder deactivation mechanism, the fuel injection mechanism, the EGR valve and the VGT supercharger, so that the engine operates in a first mode, in which the cylinder deactivation mechanism and the VGT supercharger are in an operating state, the EGR valve stops working, and the fuel pre-injection function and the fuel main injection function of the fuel injection mechanism are started, and the fuel post-injection function is disabled;

[0026] When the first temperature information is less than the first preset temperature, the second temperature information of the second SCR is obtained, and when the second temperature information is less than the second preset temperature, a second control signal is sent to the cylinder deactivation mechanism, the fuel injection mechanism, the EGR valve and the VGT supercharger to make the engine operate in a second mode. In the second mode, the cylinder deactivation mechanism stops working, the VGT supercharger and the EGR valve are in working state, and the fuel pre-injection function, the fuel main injection function and the fuel post-injection function of the fuel injection mechanism are all enabled; the first preset temperature is greater than the second preset temperature.

[0027] The embodiment of the present invention provides an exhaust temperature control system of an engine, the engine includes an engine body, a cylinder deactivation mechanism, a fuel injection mechanism, an EGR valve, and a VGT supercharger. The exhaust temperature control system includes a monitoring control module and a post-processing device. The post-processing device includes a first SCR far away from the VGT supercharger and a second SCR close to the VGT supercharger. The monitoring control module is electrically connected to the engine and the post-processing device respectively, and is used to obtain the first temperature information of the first SCR, and when the first temperature information is greater than or equal to the first preset temperature, send a first control signal to the cylinder deactivation mechanism, the fuel injection mechanism, the EGR valve and the VGT supercharger to make the engine work in the first mode, so that when it is detected that the first temperature information is greater than or equal to the first preset temperature, that is, when the post-processing device is at a normal working temperature, the first mode is switched, that is, the cylinder deactivation mechanism and the VGT supercharger are controlled to be in a working state, the EGR valve stops working, and the fuel pre-injection function and the fuel main injection function of the fuel injection mechanism are started, and the fuel post-injection function is disabled, so as to improve the fuel consumption of the engine. The monitoring and control module is also used to obtain the second temperature information of the second SCR when the first temperature information is less than the first preset temperature, and to initiate a second control signal to the cylinder deactivation mechanism, the fuel injection mechanism, the EGR valve and the VGT supercharger when the second temperature information is less than the second preset temperature, so that the engine operates in the second mode. In this way, when it is detected that the first temperature information is less than the first preset temperature and the second temperature information is less than the second preset temperature, that is, when the after-treatment device does not reach the expected temperature, the second mode is switched, that is, the cylinder deactivation mechanism is controlled to stop working, the VGT supercharger and the EGR valve are in working state, and the fuel pre-injection function, the fuel main injection function and the fuel post-injection function of the fuel injection mechanism are all enabled, so as to quickly heat up the after-treatment device to the normal operating temperature, improve the conversion efficiency of the after-treatment device, and reduce the generation of harmful emissions. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of an exhaust temperature control system of an engine provided by an embodiment of the present invention;

[0029] Figure 2 It is a flow chart of an engine exhaust temperature control method provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be fully described below in combination with the drawings in the embodiments of the present invention through specific implementation methods. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work fall within the protection scope of the present invention.

[0031] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0032] Figure 1 Schematic diagram of the structure of an engine exhaust temperature control system provided by an embodiment of the present invention. Figure 1 The engine 10 includes an engine body 110, a cylinder deactivation mechanism 120, a fuel injection mechanism 130, an EGR valve 140, and a VGT supercharger 150. The exhaust temperature control system 20 includes a monitoring control module 210 and a post-processing device 220. The post-processing device 220 includes a first SCR far from the VGT supercharger 150 and a second SCR close to the VGT supercharger 150. The monitoring control module 210 is electrically connected to the engine 10 and the post-processing device 220, and is used to obtain first temperature information of the first SCR, and when the first temperature information is greater than or equal to a first preset temperature, send a first control signal to the cylinder deactivation mechanism 120, the fuel injection mechanism 130, the EGR valve 140, and the VGT supercharger 150, so that the engine 10 operates in a first mode, in which the cylinder deactivation mechanism 120 and the VGT supercharger 150 are in a working state, the EGR valve 140 stops working, and the fuel pre-injection function and the fuel main injection function of the fuel injection mechanism 130 are started, and the fuel post-injection function is disabled. The monitoring control module 210 is also used to obtain the second temperature information of the second SCR when the first temperature information is less than the first preset temperature, and send a second control signal to the cylinder deactivation mechanism 120, the fuel injection mechanism 130, the EGR valve 140 and the VGT supercharger 150 when the second temperature information is less than the second preset temperature, so that the engine 10 operates in the second mode. In the second mode, the cylinder deactivation mechanism 120 stops working, the VGT supercharger 150 and the EGR valve 140 are in working state, and the fuel pre-injection function, the fuel main injection function and the fuel post-injection function of the fuel injection mechanism 130 are all enabled. The first preset temperature is greater than the second preset temperature.

[0033] Specifically, the engine body 110 includes a plurality of cylinders, and the plurality of cylinders are connected to the cylinder deactivation mechanism 120. When the cylinder deactivation mechanism 120 is in a working state, the intake valve and the exhaust valve of one or more cylinders can be controlled to stop working and be in a closed state according to the control signal of the monitoring control module 210, thereby entering the cylinder deactivation mode. When the cylinder deactivation mechanism 120 stops working, all cylinders in the engine body 110 participate in normal operation. It should be noted that when the cylinder deactivation mechanism 120 is in a working state, in order to maintain the power stability of the engine 10, the load of the remaining cylinders will be increased, so that the remaining cylinders are in a more efficient working state, thereby improving fuel economy, that is, improving the fuel consumption of the engine 10, and increasing the exhaust temperature of the engine 10.

[0034] The fuel injection system 130 can stop fuel injection in one or more cylinders in the engine body 10 according to the control signal of the monitoring control module 210, and cooperate with the cylinder deactivation mechanism 120 to realize the cylinder deactivation function. In addition, the fuel injection system 130 can also add a fuel post-injection function after performing the fuel pre-injection function and the fuel main injection function according to the control signal of the monitoring control module 210, which can effectively increase the exhaust temperature.

[0035] The EGR valve 140 can adjust the opening in real time according to the control signal of the monitoring control module 210, so that the exhaust gas in the exhaust pipe of the engine body 110 enters the intake system of the engine body 110 through the EGR valve 140. The exhaust gas and air are mixed and then enter the cylinder for combustion. Since part of the exhaust gas participates in the combustion, on the one hand, the exhaust temperature can be increased, and on the other hand, the combustion temperature can be reduced, thereby inhibiting the formation of nitrogen oxides in the engine exhaust gas, thereby achieving the effect of reducing the exhaust emissions of the engine 10.

[0036] The VGT supercharger 150 can adjust the opening in real time according to the control signal of the monitoring control module 210, thereby changing the intake pressure and exhaust pressure, providing the engine 10 with a suitable amount of fresh intake air and exhaust gas recirculation, thereby controlling the exhaust temperature of the engine 10.

[0037] The post-processing device 220 includes a Figure 1The second SCR, DOC, DPF and first SCR (the arrow in the middle is pointing to the downstream direction). Among them, the second SCR is located in the after-treatment device 220 near the VGT supercharger 150, that is, the second SCR is a pre-device for purifying NOx emissions in the engine exhaust, and the first SCR is located in the after-treatment device 220 away from the VGT supercharger 150, that is, the first SCR is the main device for purifying NOx emissions in the engine exhaust. The two SCR devices can fully process the NOx emissions in the engine exhaust and reduce the final NOx emissions, which is a necessary configuration to cope with future emission regulations. It should be noted that the volume of the first SCR is T1, the volume of the second SCR is T2, and the first SCR and the second SCR satisfy: 1 / 4≤T2 / T1≤1 / 2. The volume of the SCR is related to the exhaust gas purification efficiency, that is, the larger the volume of the SCR, the higher the exhaust gas purification efficiency. To reduce costs, the volume of the second SCR can be set smaller than the first SCR, that is, the volume of the pre-device is smaller than the volume of the main device. For example, the volume of the second SCR can be half or one-third of the volume of the first SCR.

[0038] The monitoring control module 210 is electrically connected to the engine 10 and the post-processing device 220, that is, the monitoring control module 210 is electrically connected to the cylinder deactivation mechanism 120, the fuel injection mechanism 130, the EGR valve 140 and the VGT supercharger 150 in the engine 10, and is electrically connected to the first SCR and the second SCR in the post-processing device 220. The monitoring control module 210 is used to obtain the first temperature information of the first SCR, and when the first temperature information is greater than or equal to the first preset temperature, send a first control signal to the cylinder deactivation mechanism 120, the fuel injection mechanism 130, the EGR valve 140 and the VGT supercharger 150, so that the engine 10 works in the first mode, that is, when it is detected that the first temperature information of the first SCR is at the normal working temperature (the first temperature information is greater than or equal to the first preset temperature), the working mode of the engine 10 is switched to the first mode. In the first mode, the cylinder deactivation mechanism 120 and the VGT supercharger 150 are in the working state, and the cylinder deactivation mechanism 120 in the working state enters the cylinder deactivation mode, and some cylinders stop working, thereby reducing fuel consumption. The EGR valve 140 is controlled to stop working, that is, the exhaust gas from the exhaust pipe in the engine body 110 will not pass through the EGR valve 140 and enter the intake system of the engine body 110. The fuel pre-injection function and the fuel main injection function of the fuel injection mechanism 130 are started, and the fuel post-injection function is disabled, thereby further reducing the fuel consumption of the engine 10.

[0039] When the monitoring control module 210 detects that the first temperature information is less than the first preset temperature, the second temperature information of the second SCR is obtained, and when the second temperature information is less than the second preset temperature, a second control signal is sent to the cylinder deactivation mechanism 120, the fuel injection mechanism 130, the EGR valve 140 and the VGT supercharger 150, so that the engine 10 operates in the second mode, that is, when it is detected that the temperature of the post-processing device 220 does not reach the expected temperature (the first temperature information is less than the first preset temperature, and the second temperature information is less than the second preset temperature), the engine 10 is switched to operate in the second mode. In the second mode, the cylinder deactivation mechanism 120 stops working (that is, all cylinders of the engine body 110 work normally, and the fuel consumption is relatively large at this time), the VGT supercharger 150 and the EGR valve 140 are in working state, and the fuel pre-injection function, the fuel main injection function and the fuel post-injection function of the fuel injection mechanism 130 are all enabled, so that the post-processing device 220 is quickly heated to the normal operating temperature, the conversion efficiency of the post-processing device 220 is improved, and the generation of harmful emissions is reduced.

[0040] It is understandable that the VGT supercharger 150 can provide the engine with a suitable amount of fresh air intake and exhaust gas recirculation, thereby controlling the exhaust temperature of the engine. The EGR valve 140 can allow the exhaust gas in the exhaust pipe of the engine body 110 to enter the intake system of the engine body 110, and the exhaust gas and air are mixed and then enter the cylinder for combustion. Since part of the exhaust gas participates in the combustion, the exhaust temperature can be increased. And after performing the fuel pre-injection function and the fuel main injection function, the fuel post-injection function is added, which can also effectively increase the exhaust temperature. Therefore, in the second mode, rapid temperature rise is achieved by deactivating the cylinder deactivation mechanism, activating the VGT supercharger and the EGR valve, and adding the fuel post-injection function after performing the fuel pre-injection function and the fuel main injection function.

[0041] It should be noted that the first preset temperature is greater than the second preset temperature. The first preset temperature may be in the range of 200°C to 220°C, and the second preset temperature may be in the range of 180°C to 200°C.

[0042] In summary, an embodiment of the present invention provides an exhaust temperature control system of an engine, the engine includes an engine body, a cylinder deactivation mechanism, a fuel injection mechanism, an EGR valve, and a VGT supercharger. The exhaust temperature control system includes a monitoring control module and a post-processing device. The post-processing device includes a first SCR far away from the VGT supercharger and a second SCR close to the VGT supercharger. The monitoring control module is electrically connected to the engine and the post-processing device, respectively, for obtaining the first temperature information of the first SCR, and when the first temperature information is greater than or equal to the first preset temperature, sending a first control signal to the cylinder deactivation mechanism, the fuel injection mechanism, the EGR valve and the VGT supercharger, so that the engine operates in the first mode, so that when it is detected that the first temperature information is greater than or equal to the first preset temperature, that is, when the post-processing device is at a normal operating temperature, by switching the first mode, that is, controlling the cylinder deactivation mechanism and the VGT supercharger to be in a working state, the EGR valve stops working, and the fuel pre-injection function and the fuel main injection function of the fuel injection mechanism are started, and the fuel post-injection function is disabled, so as to improve the fuel consumption of the engine mainly by entering the cylinder deactivation mode through the cylinder deactivation mechanism. The monitoring and control module is also used to obtain the second temperature information of the second SCR when the first temperature information is less than the first preset temperature, and to send a second control signal to the cylinder deactivation mechanism, the fuel injection mechanism, the EGR valve and the VGT supercharger when the second temperature information is less than the second preset temperature, so that the engine operates in the second mode. In this way, when it is detected that the first temperature information is less than the first preset temperature and the second temperature information is less than the second preset temperature, that is, when the after-treatment device does not reach the expected temperature, the second mode is switched, that is, the cylinder deactivation mechanism is controlled to stop working, the VGT supercharger and the EGR valve are in working state, and the fuel pre-injection function, the fuel main injection function and the fuel post-injection function of the fuel injection mechanism are all enabled, so as to quickly heat up the after-treatment device to the normal operating temperature, improve the conversion efficiency of the after-treatment device, and reduce the generation of harmful emissions.

[0043] Optionally, based on the above embodiment, continue to refer to Figure 2 The monitoring and control module 210 is also used to obtain the oil temperature information of the engine body 110 when the second temperature information is greater than or equal to the second preset temperature, and to control the engine 10 to operate in the second mode when the oil temperature information is less than the third preset temperature, and to send a third control signal to the cylinder deactivation mechanism 120, the fuel injection mechanism 130, the EGR valve 140 and the VGT supercharger 150 when the oil temperature information is greater than or equal to the third preset temperature, so that the engine 10 operates in the third mode. In the third mode, the cylinder deactivation mechanism 120, the VGT supercharger 150 and the EGR valve 140 are all in working state, and the fuel pre-injection function and the fuel main injection function of the fuel injection mechanism 130 are started, and the fuel post-injection function is disabled, wherein the third preset temperature is lower than the second preset temperature.

[0044] Specifically, in the second mode, the cylinder deactivation mechanism 120 stops working and all cylinders in the engine body 110 are fully working. If the engine body 110 works in the second mode for a long time, it will have a greater impact on the engine body 110 and the fuel consumption will be too high. Therefore, the judgment of the oil temperature information is added to increase the transition to the third mode. Exemplarily, when it is detected that the second temperature information is greater than or equal to the second preset temperature, and the engine oil temperature information is less than the third temperature information, the engine 10 continues to operate in the second mode. If it is detected that the second temperature information is greater than or the second preset temperature, and the engine oil temperature information is greater than or equal to the third preset temperature, it indicates that the post-processing device 220 needs to be heated up, but does not need to be heated up quickly, and then the engine 10 is switched from the second mode to the third mode, that is, a third control signal is sent to the cylinder deactivation mechanism 120, the fuel injection mechanism 130, the EGR valve 140 and the VGT supercharger 150, so that the engine 10 operates in the third mode. In the third mode, the cylinder deactivation mechanism 120, the VGT supercharger 150 and the EGR valve 140 are all in working condition, and the fuel pre-injection function and the fuel main injection function of the fuel injection mechanism 130 are started, and the fuel post-injection function is disabled, so that fuel consumption can be reduced on the basis of heating.

[0045] It should be noted that the third preset temperature is lower than the second preset temperature and lower than the first preset temperature. The third preset temperature may range from 40°C to 50°C.

[0046] It is understood that in the first mode, the cylinder deactivation mechanism 120 determines the first cylinder deactivation information according to the rotation speed and load of the engine body 110, and operates with the first cylinder deactivation information, and the first cylinder deactivation information includes the first cylinder deactivation area, the first cylinder deactivation number and the first cylinder deactivation combination. In the third mode, the cylinder deactivation mechanism 120 determines the second cylinder deactivation information according to the rotation speed and load of the engine body 110, and operates with the second cylinder deactivation information, and the first cylinder deactivation information includes the second cylinder deactivation area, the second cylinder deactivation number and the second cylinder deactivation combination. Since the rotation speed and load of the engine body 110 in different modes are different, the first cylinder deactivation information in the first mode is different from the second cylinder deactivation information in the third mode. It should be noted that the cylinder deactivation combination refers to the cylinder sequence number that enters the cylinder deactivation mode under the same cylinder deactivation number. For example, when the cylinder deactivation number of a 6-cylinder engine is 2, the 1st and 6th cylinders can be stopped at the same time, or the 2nd and 5th cylinders can be stopped at the same time, or the 1st and 6th cylinders and the 2nd and 5th cylinders can be stopped alternately, and the embodiment of the present invention is not limited to this.

[0047] Furthermore, the second cylinder deactivation area is larger than the first cylinder deactivation area. In other words, the second cylinder deactivation information is larger than the first cylinder deactivation information (the second cylinder deactivation area is larger than the first cylinder deactivation area, and the second cylinder deactivation number is larger than the first cylinder deactivation number). Specifically, in the first mode, since the main consideration is to reduce fuel consumption, the rising speed of the engine exhaust temperature is not restricted. In the third mode, the heating speed also needs to be considered. Therefore, it is necessary to set the second cylinder deactivation area larger than the first cylinder deactivation area to ensure that the heating speed is faster in the third mode. It should be noted that the size of the cylinder deactivation area represents the load rate of the engine. In the third mode, the engine load rate can be below 30%, and in the first mode, the engine load rate can be below 20%.

[0048] Optionally, based on the above embodiment, continue to participate Figure 1 , when the VGT supercharger is in working state, the opening information of the VGT supercharger 150 is determined according to the rotation speed and load of the engine body 110. The opening information of the VGT supercharger 150 in the second mode is greater than the opening information of the VGT supercharger 150 in the third mode, and the opening information of the VGT supercharger 150 in the third mode is greater than the opening information of the VGT supercharger 150 in the first mode. Specifically, the opening information of the VGT supercharger 150 reflects the flow area of ​​the VGT supercharger 150. The larger the opening information, the smaller the flow area, and further, the faster the engine exhaust temperature rises. Since the second mode is mainly for achieving rapid temperature rise, the opening information of the VGT supercharger 150 in the second mode is the largest, and the first mode is mainly for reducing fuel consumption, therefore, the opening information of the VGT supercharger 150 in the first mode is the smallest. The third mode is a transition state between the first mode and the second mode. At this time, it is possible to reduce fuel consumption and increase temperature (the heating rate of the third mode is lower than that of the second mode). Therefore, in the third mode, the opening information of the VGT supercharger 150 is between the first mode and the second mode.

[0049] Optionally, when the EGR valve is in a working state, the opening information of the EGR valve 140 is determined according to the rotation speed and load of the engine body 110. The opening information of the EGR valve 140 in the second mode is greater than the opening information of the EGR valve 140 in the third mode. Specifically, the opening information of the EGR valve 140 reflects the flow area of ​​the EGR valve 140. The larger the opening information of the EGR valve 140, the larger the flow area. Since the EGR valve 140 is used to circulate the exhaust gas in the exhaust pipe of the engine body 110 to the intake system of the engine body 110, the exhaust gas and air are mixed and then enter the cylinder for combustion, which can increase the exhaust temperature. Therefore, the larger the flow area of ​​the EGR valve 140, the faster the engine exhaust temperature rises. Therefore, the opening information of the EGR valve 140 in the second mode is set to be greater than the opening information of the EGR valve 140 in the third mode to ensure that the temperature can rise quickly in the second mode.

[0050] Optionally, based on the above embodiment, continue to refer to Figure 1 The monitoring control module 210 includes a first temperature sensor 211, a second temperature sensor 212, a third temperature sensor 213, a fourth temperature sensor 214 and an oil temperature sensor 215. The first temperature sensor 211 is arranged at the outlet of the first SCR, and the second temperature sensor 212 is arranged at the air inlet of the first SCR. The third temperature sensor 213 is arranged at the outlet of the second SCR, and the fourth temperature sensor 214 is arranged at the air inlet of the second SCR. The monitoring control module 210 is also used to determine the first temperature information according to the temperature information of the first temperature sensor 211 and the temperature information of the second temperature sensor 212, and to determine the second temperature information according to the temperature information of the third temperature sensor 213 and the temperature information of the fourth temperature sensor 214. The oil temperature sensor 215 is arranged on the engine body 110.

[0051] Specifically, in one embodiment, the first temperature information may be determined according to the average value of the temperature information of the first temperature sensor 211 and the temperature information of the second temperature sensor 212, and the second temperature information may be determined according to the average value of the temperature information of the third temperature sensor 213 and the temperature information of the fourth temperature sensor 214. The embodiment of the present invention does not limit the specific determination method of the first temperature information and the second temperature information, and those skilled in the art may set it as needed.

[0052] Figure 2 Schematic diagram of a flow chart of an engine exhaust temperature control method provided by an embodiment of the present invention. Figure 2 , the exhaust temperature control method comprises:

[0053] S110, obtaining first temperature information of a first SCR, and when the first temperature information is greater than or equal to a first preset temperature, sending a first control signal to a cylinder deactivation mechanism, a fuel injection mechanism, an EGR valve, and a VGT supercharger, so that the engine operates in a first mode.

[0054] In the first mode, the cylinder deactivation mechanism and the VGT supercharger are in working state, the EGR valve stops working, and the fuel pre-injection function and the fuel main injection function of the fuel injection mechanism are started, and the fuel post-injection function is disabled. Specifically, the engine body includes multiple cylinders, and the multiple cylinders are connected to the cylinder deactivation mechanism. When the cylinder deactivation mechanism is in working state, the intake valve and exhaust valve of one or more cylinders can be controlled to stop working and be in a closed state according to the control signal of the monitoring control module, thereby entering the cylinder deactivation mode. When the cylinder deactivation mechanism stops working, all cylinders in the engine body participate in normal operation. It should be noted that when the cylinder deactivation mechanism is in working state, in order to maintain the stability of the engine power, the load of the remaining cylinders will be increased, so that the remaining cylinders are in a more efficient working state, thereby improving fuel economy, that is, improving the fuel consumption of the engine. The fuel injection system can cooperate with the cylinder deactivation mechanism to realize the cylinder deactivation function. In the first mode, the fuel consumption of the engine can be reduced by controlling the cylinder deactivation mechanism to be in working state and disabling the fuel post-injection function.

[0055] S120. When the first temperature information is less than the first preset temperature, obtain the second temperature information of the second SCR, and when the second temperature information is less than the second preset temperature, send a second control signal to the cylinder deactivation mechanism, the fuel injection mechanism, the EGR valve and the VGT supercharger to make the engine operate in the second mode.

[0056] In the second mode, the cylinder deactivation mechanism stops working, the VGT supercharger and the EGR valve are in working state, and the fuel pre-injection function, the fuel main injection function and the fuel post-injection function of the fuel injection mechanism are all enabled, and the first preset temperature is greater than the second preset temperature.

[0057] Specifically, the VGT supercharger can adjust the opening in real time according to the control signal of the monitoring control module, thereby changing the intake pressure and exhaust pressure, providing the engine with a suitable amount of fresh intake air and exhaust gas recirculation, and thus controlling the exhaust temperature of the engine. The EGR valve can adjust the opening in real time according to the control signal of the monitoring control module, so that the exhaust gas in the exhaust pipe of the engine body enters the intake system of the engine body through the EGR valve, and the exhaust gas and air are mixed and enter the cylinder for combustion. Since part of the exhaust gas participates in the combustion, the exhaust temperature can be increased. And after performing the fuel pre-injection function and the fuel main injection function, the fuel post-injection function is added, which can also effectively increase the exhaust temperature. Therefore, in the second mode, the cylinder deactivation mechanism is deactivated, the VGT supercharger and the EGR valve are activated, and the fuel post-injection function is added after the fuel pre-injection function and the fuel main injection function are performed, so as to achieve rapid temperature rise.

[0058] In summary, the embodiment of the present invention operates the engine in the first mode when the first temperature information is greater than or equal to the first preset temperature, the cylinder deactivation mechanism and the VGT supercharger operate, the EGR valve stops operating, and the fuel pre-injection function and the fuel main injection function of the fuel injection mechanism are activated, and the fuel post-injection function is disabled. When the first temperature information is less than the first preset temperature, the second temperature information of the second SCR is obtained, and when the second temperature information is less than the second preset temperature, the engine operates in the second mode, the cylinder deactivation mechanism stops operating, the VGT supercharger and the EGR valve operate, and the fuel pre-injection function, the fuel main injection function, and the fuel post-injection function of the fuel injection mechanism are all enabled. In this way, in the first mode, the fuel consumption of the engine can be improved, and in the second mode, rapid temperature rise can be achieved and the generation of harmful emissions can be reduced.

[0059] An embodiment of the present invention further provides a vehicle, which includes the engine control system provided by any embodiment of the present invention.

[0060] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. An engine exhaust temperature control system, characterized in that: The engine includes an engine body, a cylinder deactivation mechanism, a fuel injection mechanism, an EGR valve, and a VGT supercharger; the exhaust temperature control system includes a monitoring control module and a post-processing device; The aftertreatment device includes a first SCR far from the VGT supercharger and a second SCR close to the VGT supercharger; The monitoring control module is electrically connected to the engine and the post-processing device, respectively, and is used to obtain first temperature information of the first SCR, and when the first temperature information is greater than or equal to a first preset temperature, sends a first control signal to the cylinder deactivation mechanism, the fuel injection mechanism, the EGR valve, and the VGT supercharger, so that the engine operates in a first mode. In the first mode, the cylinder deactivation mechanism and the VGT supercharger are in a working state, the EGR valve stops working, and the fuel pre-injection function and the fuel main injection function of the fuel injection mechanism are started, and the fuel post-injection function is disabled; The monitoring control module is further used for obtaining second temperature information of the second SCR when the first temperature information is less than the first preset temperature, and sending a second control signal to the cylinder deactivation mechanism, the fuel injection mechanism, the EGR valve and the VGT supercharger when the second temperature information is less than the second preset temperature, so as to make the engine operate in a second mode, in which the cylinder deactivation mechanism stops working, the VGT supercharger and the EGR valve are in working state, and the fuel pre-injection function, the fuel main injection function and the fuel post-injection function of the fuel injection mechanism are all enabled; The first preset temperature is greater than the second preset temperature.

2. The exhaust temperature control system according to claim 1, characterized in that: The monitoring and control module is also used to obtain the oil temperature information of the engine body when the second temperature information is greater than or equal to the second preset temperature, and to control the engine to operate in the second mode when the oil temperature information is less than a third preset temperature, and to send a third control signal to the cylinder deactivation mechanism, the fuel injection mechanism, the EGR valve and the VGT supercharger when the oil temperature information is greater than or equal to the third preset temperature, so that the engine operates in the third mode. In the third mode, the cylinder deactivation mechanism, the VGT supercharger and the EGR valve are all in working state, and the fuel pre-injection function and the fuel main injection function of the fuel injection mechanism are started, and the fuel post-injection function is disabled, wherein the third preset temperature is lower than the second preset temperature.

3. The exhaust temperature control system according to claim 2, characterized in that: In the first mode, the cylinder deactivation mechanism determines first cylinder deactivation information according to the rotation speed and load of the engine body and operates according to the first cylinder deactivation information, wherein the first cylinder deactivation information includes a first cylinder deactivation area, a first cylinder deactivation number and a first cylinder deactivation combination; In the third mode, the cylinder deactivation mechanism determines second cylinder deactivation information according to the rotation speed and load of the engine body and operates with the second cylinder deactivation information, where the second cylinder deactivation information includes a second cylinder deactivation area, a second cylinder deactivation number and a second cylinder deactivation combination.

4. The exhaust temperature control system according to claim 3, characterized in that: The second cylinder deactivation area is larger than the first cylinder deactivation area.

5. The exhaust temperature control system according to claim 2, characterized in that: When the VGT supercharger is in a working state, determining the opening information of the VGT supercharger according to the rotation speed and load of the engine body; The opening information of the VGT supercharger in the second mode is greater than the opening information of the VGT supercharger in the third mode, and the opening information of the VGT supercharger in the third mode is greater than the opening information of the VGT supercharger in the first mode.

6. The exhaust temperature control system according to claim 2, characterized in that: When the EGR valve is in a working state, determining the opening information of the EGR valve according to the rotation speed and load of the engine body; The opening information of the EGR valve in the second mode is greater than the opening information of the EGR valve in the third mode.

7. The exhaust temperature control system according to claim 1, characterized in that: The volume of the first SCR is T1, the volume of the second SCR is T2, and the second SCR and the first SCR satisfy: 1 / 4≤T2 / T1≤1 / 2.

8. The exhaust temperature control system according to claim 2, characterized in that: The monitoring control module includes a first temperature sensor, a second temperature sensor, a third temperature sensor, a fourth temperature sensor and an oil temperature sensor; The first temperature sensor is disposed at an air outlet of the first SCR, and the second temperature sensor is disposed at an air inlet of the first SCR; The third temperature sensor is disposed at the air outlet of the second SCR, and the fourth temperature sensor is disposed at the air inlet of the second SCR; The monitoring and control module is further used to determine the first temperature information according to the temperature information of the first temperature sensor and the temperature information of the second temperature sensor, and to determine the second temperature information according to the temperature information of the third temperature sensor and the temperature information of the fourth temperature sensor; The oil temperature sensor is arranged on the engine body.

9. A method for controlling exhaust temperature of an engine, characterized in that: Applicable to the exhaust temperature control system of the engine according to any one of claims 1 to 8; The exhaust temperature control method comprises: Acquiring first temperature information of the first SCR; and when the first temperature information is greater than or equal to a first preset temperature, sending a first control signal to the cylinder deactivation mechanism, the fuel injection mechanism, the EGR valve and the VGT supercharger, so that the engine operates in a first mode, in which the cylinder deactivation mechanism and the VGT supercharger are in an operating state, the EGR valve stops working, and the fuel pre-injection function and the fuel main injection function of the fuel injection mechanism are started, and the fuel post-injection function is disabled; When the first temperature information is less than the first preset temperature, the second temperature information of the second SCR is obtained, and when the second temperature information is less than the second preset temperature, a second control signal is sent to the cylinder deactivation mechanism, the fuel injection mechanism, the EGR valve and the VGT supercharger to make the engine operate in a second mode. In the second mode, the cylinder deactivation mechanism stops working, the VGT supercharger and the EGR valve are in working state, and the fuel pre-injection function, the fuel main injection function and the fuel post-injection function of the fuel injection mechanism are all enabled; the first preset temperature is greater than the second preset temperature.

10. A vehicle, characterized in that: An exhaust temperature control system for an engine comprising the method described in any one of claims 1 to 8.

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