A temperature control device and temperature control method based on PID control

Abstract

The present application provides a temperature control device and a temperature control method based on PID control, which are used to generate an operating temperature control strategy suitable for engine working conditions. The embodiment method of the present application includes: an engine body, a temperature sensor, a differential pressure sensor, an emission analyzer, and a master controller; the exhaust gas emission of the engine body is provided with an exhaust gas emission system, and the exhaust gas emission system includes a DOC oxidation catalytic converter and a DPF particulate trap, the temperature sensor and the differential pressure sensor are provided at the front end of the DOC, the rear end of the DPF, and between the DOC and the DPF, and the data acquisition sensor of the emission analyzer is provided at the front end of the DOC and the rear end of the DPF; the data acquired by the emission analyzer, the temperature sensor, and the differential pressure sensor are input into the master controller, so that the master controller acquires data for calculating temperature control.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of engines, and in particular to a temperature control device and a temperature control method based on PID control. Background Art

[0002] The after-treatment of oil engines basically adopts DOC (Diesel Oxidation Catalyst), DPF (Diesel Particulate Filter), SCR (selective catalytic reduction) and ASC (Active stability control). The after-treatment temperature is sensitive to temperature, especially low-temperature starting, and emissions exceed the standard.

[0003] In the prior art, the exhaust temperature control method is mostly to wrap the exhaust pipe with insulation material and combine diesel fuel injection at both far and near ends, but the temperature of DPF and DOC is not coordinated well, and the injection strategy is not perfect enough, resulting in emissions failing to meet regulatory requirements when the engine is running at a lower temperature. Summary of the invention

[0004] The present application provides a temperature control device and a temperature control method based on PID control, which are used to generate an operating temperature control strategy suitable for engine operating conditions.

[0005] The present application provides a temperature control device based on PID control, comprising:

[0006] Engine body, temperature sensor, differential pressure sensor, emission analyzer, master controller;

[0007] An exhaust system is provided at the exhaust emission point of the engine body, and the exhaust system includes a DOC oxidation catalytic converter and a DPF particulate trap. The temperature sensor and the pressure difference sensor are provided at the front end of the DOC, the rear end of the DPF, and between the DOC and the DPF. The data acquisition sensor of the emission analyzer is provided at the front end of the DOC and the rear end of the DPF.

[0008] The data acquired by the emission analyzer, the temperature sensor and the differential pressure sensor are input into the master controller, so that the master controller acquires data for calculating temperature control.

[0009] Optionally, the engine body includes an air intake system, an intake intercooler, an EGR exhaust gas recirculation system intercooler, a turbocharger system and a cylinder group.

[0010] Optionally, the air intake system includes an air filter and an air flow meter, the outlet end of the air filter is connected to the inlet end of the air flow meter, the outlet end for air flow calculation is connected to the first supercharger in the turbocharger system, the outlet end of the first supercharger is connected to the inlet end of the intake intercooler, the outlet end of the intake intercooler is connected to the inlet end of the cylinder group, the outlet end of the cylinder group is connected to the second supercharger in the turbocharger system, an EGR exhaust gas recirculation system is arranged between the cylinder group and the second supercharger, the EGR outlet end is connected to the EGR intercooler, and the outlet end of the second supercharger is connected to the exhaust emission system.

[0011] Optionally, the master controller includes a data acquisition system, a computer, an INCA calibration system and an ECU electronic control unit.

[0012] Optionally, the data acquisition system will obtain the data required for the computer to perform temperature control calculations through the emission analyzer, the temperature sensor and the pressure difference sensor, and send the data to the computer after acquisition. The computer calculates the data collected by the data acquisition system and sends the calculation results to the INCA calibration system for data calibration, and sends the calibration results to the ECU, so that the ECU adjusts the temperature of the exhaust emission system according to the calibration results.

[0013] Optionally, the EGR system is provided with a one-way valve so that the gas at the outlet end of the cylinder group cannot flow out after entering the EGR system.

[0014] Optionally, the measurement range of the temperature sensors provided at the DOC air inlet and the DOC air outlet is between -40 and 750 degrees Celsius, and the rated resistance of the temperature sensors is 200 ohms.

[0015] Optionally, the thermal protection material of the wire of the temperature sensor is silicone rubber, the insulation material of the temperature sensor is PTFE, and the temperature sensor is powered by 5V DC.

[0016] Optionally, the wire used by the temperature sensor is a nickel-plated copper wire, the cross-sectional area of ​​the nickel-plated copper wire is 0.5 square millimeters, and the length of the nickel-plated copper wire is 1000 millimeters.

[0017] Optionally, the heat medium of the temperature sensor is the exhaust gas discharged by the engine body, and the front end of the probe of the temperature sensor is located in the center of the detected airflow, and the detected airflows are the intake airflow of the DOC and the outlet airflow of the DOC.

[0018] A second aspect of the present application provides a temperature control method, comprising:

[0019] The main controller obtains initial data, wherein the initial data includes the inner ring temperature rise requirement, the ignition temperature and the upstream actual temperature;

[0020] The master controller calculates the initial data to obtain the ignition temperature difference;

[0021] The master controller performs PI calculation on the light-off temperature difference through a PID algorithm to obtain a light-off temperature difference PI value, and the light-off temperature difference PI value is used to correct the light-off temperature difference of the DOC oxidation catalytic converter;

[0022] The master controller calculates the first fuel injection amount and the intake air amount according to the light-off temperature difference PI value;

[0023] The master controller controls the DOC temperature to rise according to the first fuel injection amount and the intake air amount until the DOC reaches the ignition temperature;

[0024] After the DOC reaches the light-off temperature, the master controller acquires the downstream temperature of the DOC;

[0025] The master controller calculates a first downstream temperature difference according to the downstream temperature of the DOC;

[0026] The master controller calculates the first downstream temperature difference and the expected value of the oil injection amount to obtain a target downstream temperature difference;

[0027] The master controller calculates the fuel injection amount according to the target downstream temperature difference to obtain a target fuel injection amount.

[0028] Optionally, the master controller calculates the initial data to generate the ignition temperature difference, including:

[0029] The master controller obtains the DOC inner loop temperature rise requirement, the DOC ignition temperature and the DOC upstream actual temperature;

[0030] The master controller selects a ramp factor for the DOC inner loop temperature rise requirement to obtain a target DOC inner loop temperature rise requirement;

[0031] The master controller performs a ramp calculation on the target DOC inner loop temperature rise requirement, the DOC light-off temperature and the actual temperature upstream of the DOC to obtain a light-off temperature difference.

[0032] Optionally, the master controller calculates the first fuel injection amount and the intake air amount according to the light-off temperature difference PI value, including:

[0033] The master controller acquires a first fuel injection amount preset range and a first fuel injection amount minimum value;

[0034] The master controller calculates the first fuel injection amount preset range and the first fuel injection amount minimum value according to the light-off temperature difference PI value to obtain the first fuel injection amount;

[0035] The master controller obtains the air intake range and the minimum air intake value;

[0036] The master controller calculates the intake air volume range and the minimum intake air volume according to the ignition temperature difference PI value to obtain the intake air volume.

[0037] Optionally, the master controller calculates the first downstream temperature difference according to the downstream temperature of the DOC, including:

[0038] The master controller calculates the temperature difference between the downstream temperature and the standard value of the downstream temperature to obtain a preliminary downstream temperature difference;

[0039] The master controller corrects the preliminary downstream temperature difference according to the expected downstream temperature value to obtain a first downstream temperature difference.

[0040] Optionally, the master controller calculates the fuel injection amount according to the target downstream temperature difference, and obtaining the target fuel injection amount includes:

[0041] The master controller calculates the fuel injection amount according to the target downstream temperature difference to obtain a second fuel injection amount;

[0042] The master controller obtains the feedback value of the DOC to obtain the required oil volume;

[0043] The master controller determines whether the second fuel injection amount is less than the required fuel amount;

[0044] If yes, the master controller determines the second fuel injection amount as the target fuel injection amount;

[0045] If not, the master controller determines the required fuel quantity as the target fuel injection quantity.

[0046] It can be seen from the above technical solution that the present application obtains the operating temperature of DOC and DPF and monitors the exhaust emissions of DOC and DPF through an emission analyzer, so that the main controller obtains sufficient data for analysis and formulates a temperature control strategy. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 This is a schematic diagram of the structure of an embodiment of a temperature control device based on PID control in an embodiment of the present application;

[0048] Figure 2 This is a flow chart of an embodiment of the temperature control method in the embodiments of the present application;

[0049] Figure 3This is a flow chart of another embodiment of the temperature control method in the embodiment of the present application. DETAILED DESCRIPTION

[0050] In the present invention, the directions or positional relationships indicated by terms such as “upper”, “lower”, “left”, “right”, “front”, “back”, “top”, “bottom”, “inside”, “outside”, “middle”, “vertical”, “horizontal”, “lateral” and “longitudinal” are based on the directions or positional relationships shown in the accompanying drawings, and are only used to illustrate the relative positional relationships between the various components or components, and do not particularly limit the specific installation directions of the various components or components.

[0051] In addition, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to specific circumstances.

[0052] In addition, the terms "installed", "set", "provided with", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0053] In addition, the structures, proportions, sizes, etc. drawn in the drawings in the present application are only used to match the contents disclosed in the specification for the technical personnel in this field to understand and read, and are not used to limit the restrictive conditions under which the present application can be implemented. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed in the present application without affecting the effects and purposes that can be achieved by the present application.

[0054] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0055] An embodiment of the present application provides a closed-loop temperature control device for an exhaust emission system based on PID control, which is used to generate an operating temperature control strategy suitable for engine operating conditions.

[0056] See also Figure 1The present application provides an embodiment of a temperature control device based on PID control, including:

[0057] Engine body 1, temperature sensor 2, differential pressure sensor 3, emission analyzer 4, master controller 5;

[0058] The exhaust gas emission part of the engine body 1 is provided with an exhaust gas emission system 6, and the exhaust gas emission system includes a DOC oxidation catalytic converter 61 and a DPF particulate trap 62. The temperature sensor 63 and the pressure difference sensor 64 are provided at the front end of the DOC 61, the rear end of the DPF 62, and between the DOC 61 and the DPF 62. The data acquisition sensor of the emission analyzer 4 is provided at the front end of the DOC 61 and the rear end of the DPF 62.

[0059] The data acquired by the emission analyzer 4 , the temperature sensor 2 , and the differential pressure sensor 3 are input into the master controller 5 , so that the master controller 5 acquires data for calculating temperature control.

[0060] Specifically, the embodiment of the present application, based on the basic working principle of the engine, adds a temperature feedback control strategy of DOC (Diesel Oxidation Catalyst) and DPF (Diesel Particulate Filter), divides the exhaust temperature control strategy into two parts: inner loop control and outer loop control, and uses PID to correct the temperature, so that the distribution of post-injection fuel amount is more reasonable and the fuel economy is improved.

[0061] In actual situations, exhaust temperature control is controlled by the amount of fuel injected after the injection, and the accurate calculation of the amount of fuel injected at present required by the engine requires a comprehensive analysis of the relevant curves of vehicle speed, external ambient temperature, and catalyst thermal tolerance. The exhaust emission system mainly processes the exhaust gas generated when the engine is running, and the temperature sensor and pressure difference sensor are used to measure the vehicle speed and external ambient temperature during the engine assembly and vehicle operation. The data of the catalyst thermal tolerance curve has been obtained during the engine development process, so in actual situations, the engine needs to obtain accurate calculation demand data to support the calculation of engine temperature control.

[0062] Specifically, a DOC and a DPF are provided in the exhaust emission system of the engine. The DOC is used to catalyze oxides and the DPF is used to adsorb solid particles. Both components are used to purify the exhaust gas generated by the engine. However, the DOC and the DPF have high requirements for the working temperature. In order to ensure that the DOC can better catalyze the oxides, it is necessary to regulate its working temperature. Therefore, a temperature sensor and a differential pressure sensor are provided at the air inlet and air outlet ends of the DOC and the air inlet and air outlet ends of the DPF. The temperature sensor and the differential pressure sensor can be an integrated temperature and pressure differential sensor, and sensing contacts of the emission analyzer are respectively provided at the total air inlet and air outlet ends of the exhaust emission system, so that the emission analyzer can obtain the exhaust gas status data at the air inlet and air outlet ends through the contacts, and feed back the status to the data acquisition system, so that the computer can reasonably regulate the temperature of the exhaust emission system through the data provided by the data acquisition system.

[0063] Optionally, the engine body 1 includes an air intake system 11 , an intake intercooler 12 , an EGR exhaust gas recirculation system intercooler 13 , a turbocharger system 14 and a cylinder group 15 .

[0064] Specifically, the engine body must at least meet the requirements of a complete engine body consisting of an air intake system, an intake intercooler, an EGR exhaust gas recirculation system intercooler, a turbocharger system and a cylinder group, wherein the air intake system is used to inhale air so that the air flows into the cylinder as a combustion aid.

[0065] Optionally, the air intake system 11 includes an air filter 111 and an air flow meter 112, the outlet end of the air filter 111 is connected to the inlet end of the air flow meter 112, the outlet end of the air flow meter 112 is connected to the first supercharger 141 in the turbocharger system 14, the outlet end of the first supercharger 141 is connected to the inlet end of the intake intercooler 12, the outlet end of the intake intercooler 12 is connected to the inlet end of the cylinder group 15, the outlet end of the cylinder group 15 is connected to the second supercharger 142 in the turbocharger system 14, an EGR exhaust gas recirculation system 7 is arranged between the cylinder group 15 and the second supercharger 142, the EGR outlet end is connected to the EGR intercooler 13, and the outlet end of the second supercharger 142 is connected to the exhaust gas emission system 6.

[0066] Specifically, before the air enters the engine, it needs to be purified by an air filter, and the air entering the engine is measured by an air flow meter before entering the first supercharger. The first supercharger mainly acts on the air entering the engine, and the second supercharger acts on the exhaust gas discharged from the engine body.

[0067] After the air enters the engine body, it will first be pressurized by the first supercharger of the turbocharger system. To prevent the air from overheating after passing through the turbocharger system, it will first be cooled by the intake intercooler before entering the cylinder. A one-way valve is installed in the pipe of the intake intercooler to the cylinder, so that the air can only enter but not flow back.

[0068] The exhaust gas generated by cylinder combustion will be discharged into the exhaust emission system through the supercharger and then discharged from the engine. In order to avoid energy waste, an oil-gas separator will be used when the exhaust gas is discharged from the cylinder, so that the incompletely burned energy can re-enter the cylinder through the exhaust gas recirculation system. One end of the exhaust gas recirculation system is connected to the air outlet of the cylinder, and the other end is set at the rear end of the one-way valve set in the pipe connecting the intake intercooler and the cylinder. Before entering the cylinder, the separated exhaust gas will be cooled by the EGR intercooler.

[0069] Optionally, the master controller 5 includes a data acquisition system 51 , a computer 52 , an INCA calibration system 53 and an ECU electronic control unit 54 .

[0070] In actual situations, the role of the master controller is to calculate and execute the temperature control plan of the exhaust emission system. Among them, the data acquisition system is used to obtain the engine operating parameters that need to be obtained from the engine when the computer calculates. The computer is used to analyze and calculate the obtained parameters to obtain the temperature adjustment plan of the exhaust emission system. The INCA calibration system is used to correct the temperature adjustment plan generated by the engine. The ECU is the on-board computer, which is used to execute the corrected temperature adjustment plan.

[0071] Optionally, the data acquisition system 51 will obtain the data required for the computer to perform temperature control calculations through the emission analyzer 4, the temperature sensor 2 and the pressure difference sensor 3, and send the data to the computer 52 after acquisition. The computer 52 calculates the data collected by the data acquisition system 51, and sends the calculation results to the INCA calibration system 53 for data calibration, and sends the calibration results to the ECU 54, so that the ECU 54 adjusts the temperature of the exhaust emission system according to the calibration results.

[0072] Specifically, all modules in the master controller are mainly connected for data communication. After the data acquisition system obtains the data fed back by the emission analyzer, temperature sensor and differential pressure sensor, the data acquisition system will send the obtained data to the computer, so that the computer can calculate the temperature of the exhaust emission system according to the obtained data. After the calculation result is obtained, the result is sent to INCA for calibration, and finally the calibration result is sent to the ECU so that the ECU can adjust the temperature of the exhaust emission system according to the result.

[0073] Optionally, the EGR system 7 is provided with a one-way valve so that the gas at the outlet end of the cylinder group 15 cannot flow out after entering the EGR system 7 .

[0074] Specifically, in order to avoid the waste of energy caused by the backflow and leakage of gas entering the EGR, a one-way valve is provided at the intake end of the EGR system.

[0075] The measurement range of the temperature sensor 63 provided at the air inlet end and the air outlet end of the DOC 61 is between -40 and 750 degrees Celsius, and the rated resistance of the temperature sensor 63 is 200 ohms.

[0076] Specifically, the temperature sensors at the DOC inlet and outlet ends are mainly used to sense the temperature of the DOC. The measurement range of the temperature sensor is -40 to 750 degrees Celsius, and the rated resistance is 200 ohms. The temperature sensor within this range can adapt to the temperature sensing of the engine in extreme environments.

[0077] The thermal protection material of the wire of the temperature sensor 63 is silicone rubber, the insulation material of the temperature sensor is PTFE, and the temperature sensor is powered by 5V DC.

[0078] Specifically, the temperature sensor needs to be powered by a wire, but the working environment of the temperature sensor is harsh. The wire needs to be covered with thermal protection material when connecting the temperature sensor. In order to prevent wire leakage under high temperature conditions from affecting the temperature sensor, an insulating material PTFE is also attached to the outside of the temperature sensor. In actual situations, the rated voltage of the temperature sensor is 5V.

[0079] Optionally, the wire used by the temperature sensor 63 is a nickel-plated copper wire, the cross-sectional area of ​​the nickel-plated copper wire is 0.5 square millimeters, and the length of the nickel-plated copper wire is 1000 millimeters.

[0080] Specifically, the wire of the temperature sensor is nickel-plated copper wire. There is almost no difference in temperature and electrical properties between nickel-plated copper wire and bare copper wire. The difference is that the nickel plating layer is very stable in the air. The cross-sectional area of ​​the nickel-plated copper wire is 0.5 square millimeters and its length is 1000 millimeters.

[0081] Optionally, the heat medium of the temperature sensor 63 is the exhaust gas discharged by the engine body, and the front end of the probe of the temperature sensor is located in the center of the detected airflow, and the detected airflows are the intake airflow of the DOC and the outlet airflow of the DOC, so the probe of the temperature sensor cannot be located in the dead zone.

[0082] Specifically, the contacts of the temperature sensor are located at the air inlet and air outlet of the DOC, so that the medium for sensing the temperature is the exhaust gas discharged by the engine body, and the working temperature of the DOC and PDF is measured by the exhaust gas temperature.

[0083] It can be seen from the above technical solution that the present application obtains the operating temperature of DOC and DPF and monitors the exhaust emissions of DOC and DPF through an emission analyzer, so that the main controller obtains sufficient data for analysis and formulates a temperature control strategy.

[0084] The above is a detailed description of the temperature control device based on PID control in the embodiment of the present application, and the temperature control method will be described next.

[0085] See also Figure 2 The present application provides an embodiment of a temperature control method, including:

[0086] 201. The main controller obtains initial data, where the initial data includes the inner ring temperature rise requirement, the ignition temperature, and the upstream actual temperature;

[0087] In actual situations, the method is implemented by the above device.

[0088] The fuel injection of the engine is divided into three modes: pre-injection, main injection and post-injection. The method provided in the embodiment of the present application is mainly used to calculate the injection amount of the post-injection, and to control the temperature of the engine after-treatment system by accurately controlling the injection amount of the post-injection.

[0089] Specifically, the master controller refers to the vehicle master controller used to calculate and control the acquired vehicle data; the initial data refers to the data that needs to be monitored when the vehicle is running, including but not limited to: vehicle speed, external ambient temperature, relevant curves of the catalyst's thermal tolerance, Maipu correction, consideration of the amount of oil lost due to post-injection, and the amount of oil feedback due to DOC heating. The specifics are not limited here, but at least include the inner ring heating requirement, ignition temperature and actual upstream temperature.

[0090] 202. The master controller calculates the initial data to obtain an ignition temperature difference;

[0091] Specifically, after the main controller obtains the initial data, the main controller will calculate the DOC ignition temperature difference based on the DOC related data obtained at this time and the preset fixed parameters. The ignition temperature difference is the difference between the engine and the standard ignition safety temperature in the current state. The main controller generates the ignition temperature difference by calculating the temperature.

[0092] 203. The master controller performs PI calculation on the light-off temperature difference through a PID algorithm to obtain a light-off temperature difference PI value, and the light-off temperature difference PI value is used to correct the light-off temperature difference of the DOC oxidation catalytic converter;

[0093] Specifically, the vehicle-mounted system calculates the PI value of the DOC light-off temperature difference, mainly by inputting the DOC light-off temperature difference into a preset PID algorithm and then calculating the PI value of the light-off temperature difference through the PID algorithm.

[0094] 204. The master controller calculates a first fuel injection amount and an intake air amount according to the light-off temperature difference PI value;

[0095] Specifically, after the light-off temperature difference PI value is obtained, the PI value is input into the limiting module, so that the limiting module calculates the first fuel injection amount and the intake air amount according to the light-off temperature difference PI value, wherein the first fuel injection amount is the fuel injection amount of the post-injection 2 .

[0096] 205. The master controller controls the DOC temperature to rise according to the first fuel injection amount and the intake air amount until the DOC reaches the ignition temperature;

[0097] Specifically, after calculating the first fuel injection amount and air intake amount, the main controller will control the air intake at the post-injection 2nd stage intake end. Because the fuel injection amount is directly related to the increased temperature, in order to reach the DOC ignition temperature, the first fuel injection amount and air intake amount are the optimal fuel injection amount and air intake amount that can enable the DOC to reach the ignition temperature without causing energy waste.

[0098] 206. After the DOC reaches the ignition temperature, the master controller acquires the downstream temperature of the DOC;

[0099] After performing post-injection 2, the injection amount of post-injection 1 must be calculated. Post-injection 1 is used to control the subsequent environment temperature after the DOC reaches the ignition temperature, mainly by controlling the acquired downstream temperature of the DOC.

[0100] 207. The master controller calculates a first downstream temperature difference according to the downstream temperature of the DOC;

[0101] Specifically, in order to determine the fuel injection amount of the post-injection 1 , the master controller needs to determine the first downstream temperature difference before calculating the fuel injection amount. The first downstream temperature difference is necessary data for calculating the fuel injection amount of the post-injection 1 .

[0102] 208. The master controller calculates the first downstream temperature difference and the expected value of the oil injection amount to obtain a target downstream temperature difference;

[0103] Specifically, after determining the first downstream temperature difference, the master controller calculates an expected value of the post-injection 1 oil quantity injection under the temperature difference, and corrects the first downstream temperature difference based on the expected value, thereby obtaining a target downstream temperature difference.

[0104] 209. The master controller calculates the fuel injection amount according to the target downstream temperature difference to obtain a target fuel injection amount.

[0105] Specifically, after the master controller confirms the target downstream temperature difference, the master controller will calculate the fuel injection amount of the post-injection 1 according to the target downstream temperature difference, thereby obtaining the target fuel injection amount of the post-injection 1 .

[0106] It can be seen from the above technical solution that the present application obtains multiple initial data through the main controller and performs PID calculation on them, so as to accurately calculate or correct the engine's fuel injection amount, and reduce fuel consumption by accurately controlling the fuel injection amount.

[0107] See also Figure 3 , the present application embodiment provides another embodiment of the temperature control method, the method comprising:

[0108] 301. The main controller obtains initial data, where the initial data includes the inner ring temperature rise requirement, the ignition temperature, and the upstream actual temperature;

[0109] Step 301 in this embodiment is similar to step 201 in the above embodiment and will not be described again here.

[0110] 302. The master controller obtains the DOC inner loop temperature rise requirement, the DOC ignition temperature and the DOC upstream actual temperature;

[0111] Specifically, the DOC inner loop temperature rise requirement, DOC ignition temperature and DOC upstream actual temperature are data preset in the master controller. Their main function is to serve as parameters for calculating the DOC ignition temperature difference to ensure the reference of the subsequently calculated PI value.

[0112] 303. The master controller selects a ramp factor for the DOC inner loop temperature rise requirement to obtain a target DOC inner loop temperature rise requirement;

[0113] Specifically, the main controller will select a ramp factor for the DOC inner loop heating demand. At this time, the main controller will obtain a pair of parameters including a positive slope and a negative slope, and use them as parameters for selecting the ramp factor for the DOC inner loop heating demand. The output result of the ramp factor selection is the target DOC inner loop heating demand.

[0114] 304. The master controller performs a ramp calculation on the target DOC inner loop temperature rise requirement, the DOC ignition temperature, and the actual DOC upstream temperature to obtain a ignition temperature difference.

[0115] Specifically, after the main controller obtains the target DOC inner loop temperature rise demand, it will perform a ramp calculation on the temperature difference calculated between the target DOC inner loop temperature rise demand and the DOC ignition temperature and the actual DOC upstream temperature, thereby obtaining the ignition temperature difference. The ramp calculation is to make a reasonable correction to the final DOC ignition temperature difference so that it remains within a reasonable range for subsequent calculations.

[0116] 305. The master controller performs PI calculation on the light-off temperature difference through a PID algorithm to obtain a light-off temperature difference PI value, and the light-off temperature difference PI value is used to correct the light-off temperature difference of the DOC oxidation catalytic converter;

[0117] Step 305 in this embodiment is similar to step 203 in the above embodiment and will not be described again here.

[0118] 306. The master controller obtains a first fuel injection amount preset range and a first fuel injection amount minimum value;

[0119] Specifically, the first fuel injection amount refers to the fuel injection amount of the rear injection 2. The main controller has a preset range for the fuel injection amount of the rear injection 2, and the fuel injection amount of the rear injection 2 can only be adjusted within this range. Because the size of the fuel injection amount is directly related to the working temperature of the post-processing system, to prevent the temperature from being too high, the main controller will set a threshold value for the fuel injection amount of the rear injection 2, and set the first minimum fuel injection amount to limit the fuel injection amount. The inevitable adjustment effect on the working temperature of the post-processing system will be produced.

[0120] 307. The master controller calculates the first fuel injection amount preset range and the first fuel injection amount minimum value according to the light-off temperature difference PI value to obtain the first fuel injection amount;

[0121] Specifically, the main controller will process the PI value of the ignition temperature difference through the limiting module, and calculate the first injection amount within the preset range of the first injection amount according to the processing result, so as to ensure that the calculated injection amount of the post-injection 2 is used to adjust the temperature after injection to meet the working temperature requirements of the post-processing system.

[0122] 308. The main controller obtains an air intake range and a minimum air intake value;

[0123] Specifically, the main controller will correct the PI value processed by the idle module according to the preset range of the intake volume and the minimum value of the intake volume. The intake volume range and the minimum value of the intake volume are preset data of the main controller.

[0124] 309. The master controller calculates the intake air volume range and the minimum intake air volume according to the ignition temperature difference PI value to obtain the intake air volume.

[0125] Specifically, after limiting the PI value of the ignition temperature difference through the limiting module, the main controller will calculate the intake volume according to the corrected PI value of the ignition temperature difference. During the calculation process, the main controller will obtain the system fault detection identifier, and logically invert the fault identifier as the flag for calculating the intake volume. If an abnormality occurs, the main controller will stop calculating the intake volume and only adjust the temperature of the post-treatment system through the injection amount of post-injection 2.

[0126] 310. The master controller controls the DOC temperature to rise according to the first fuel injection amount and the intake air amount until the DOC reaches the ignition temperature;

[0127] 311. After the DOC reaches the ignition temperature, the master controller obtains the downstream temperature of the DOC;

[0128] Steps 310 to 311 in this embodiment are similar to steps 205 to 206 in the above embodiment, and are not described again here.

[0129] 312. The master controller calculates the temperature difference between the downstream temperature and the downstream temperature standard value to obtain a preliminary downstream temperature difference;

[0130] Specifically, after the master controller obtains the downstream temperature of the DOC, the master controller will perform calculations based on the current downstream temperature and the standard value of the downstream temperature to determine a preliminary downstream temperature difference.

[0131] 313. The master controller corrects the preliminary downstream temperature difference according to the expected downstream temperature value to obtain a first downstream temperature difference.

[0132] Specifically, the expected value of the downstream temperature is the downstream temperature difference value obtained by temperature indexing the DOC model temperature through the DOC downstream temperature difference model and calculating it with the exhaust mass flow rate of the post-processing cylinder and filtering it through a recorder through preset proportional parameters and filtering time.

[0133] 314. The master controller calculates the first downstream temperature difference and the expected value of the oil injection amount to obtain a target downstream temperature difference;

[0134] Step 314 in this embodiment is similar to step 208 in the above embodiment and will not be described again here.

[0135] 315. The master controller calculates the fuel injection amount according to the target downstream temperature difference to obtain a second fuel injection amount;

[0136] Specifically, after obtaining the target downstream temperature difference, the main controller will calculate the DOC feedback oil quantity according to the exhaust mass volume of the after-treatment system, the DOC desired temperature, the DOC temperature model and the open-loop control activation state to obtain the second injection quantity.

[0137] 316. The master controller obtains the feedback value of the DOC to obtain the required oil volume;

[0138] Specifically, the DOC feedback value is a value fed back directly to the main controller by the DOC, and the vehicle-mounted slave terminal directly calculates the feedback value to obtain a value obtained when other components of the engine are operating normally, and the value is the required fuel volume.

[0139] 317. The master controller determines whether the second fuel injection amount is less than the required fuel amount;

[0140] Specifically, the second fuel injection amount refers to the fuel injection amount obtained after the open-loop calculation of the post-injection 1, and the required fuel amount is the fuel amount directly calculated by the master controller through the feedback value of the DOC. In order to reduce the energy consumption of the engine, in actual situations, the data with a smaller fuel injection amount will be selected as the target fuel injection amount of the post-injection 1 after judgment. If the judgment result is yes, step 318 is executed, and if the judgment result is no, step 319 is executed.

[0141] 318. Determine the second fuel injection amount as a target fuel injection amount;

[0142] Specifically, when the second fuel injection amount is less than the required fuel amount, the main controller sets the second fuel injection amount as the target fuel injection amount of the post-injection 1, and controls the post-injection 1 to inject fuel according to the target fuel injection amount to achieve the purpose of temperature control.

[0143] 319. Determine the required fuel quantity as the target fuel injection quantity.

[0144] Specifically, when the second fuel injection amount is greater than the required fuel injection amount, the main controller sets the required fuel injection amount as the target fuel injection amount of the post-injection 1, and controls the post-injection 1 to inject fuel according to the target fuel injection amount, thereby achieving the purpose of temperature control.

[0145] In the embodiment of the present application, the specific data required for calculation in each step is accurately calculated, so that the calculation process of the injection amount of post-injection 1 and post-injection 2 is clearer.

[0146] It can be seen from the above technical solution that the present application obtains multiple initial data through the main controller and performs PID calculation on them, so as to accurately calculate or correct the engine's fuel injection amount, and reduce fuel consumption by accurately controlling the fuel injection amount.

[0147] It should be noted that the above description of the disclosed embodiments enables professionals and technicians in the field to implement or use the present application. Various modifications to these embodiments will be apparent to professionals and technicians in the field, and the general principles defined herein can be implemented in other embodiments without departing from the scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but should conform to the widest scope consistent with the principles and novel features disclosed herein.

[0148] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0149] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be an indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0150] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0151] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0152] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, read-only memory), random access memory (RAM, random access memory), disk or optical disk and other media that can store program code.

Claims

1. A temperature control device based on PID control, characterized in that: include: Engine body, temperature sensor, differential pressure sensor, emission analyzer, master controller; An exhaust system is provided at the exhaust emission point of the engine body, and the exhaust system includes a DOC oxidation catalytic converter and a DPF particulate trap. The temperature sensor and the pressure difference sensor are provided at the front end of the DOC, the rear end of the DPF, and between the DOC and the DPF. The data acquisition sensor of the emission analyzer is provided at the front end of the DOC and the rear end of the DPF. The data acquired by the emission analyzer, the temperature sensor and the differential pressure sensor are input into the master controller, so that the master controller acquires data for calculating temperature control; The engine body includes an air intake system, an intake intercooler, an EGR intercooler, a turbocharger system and a cylinder group; The air intake system comprises an air filter and an air flow meter, wherein the air outlet of the air filter is connected to the air inlet of the air flow meter, the air outlet of the air flow meter is connected to the first supercharger in the turbocharger system, the air outlet of the first supercharger is connected to the air inlet of the air intake intercooler, the air outlet of the air intake intercooler is connected to the air inlet of the cylinder group, the air outlet of the cylinder group is connected to the second supercharger in the turbocharger system, an EGR exhaust gas recirculation system is arranged between the cylinder group and the second supercharger, the air outlet of the exhaust gas recirculation system is connected to the EGR intercooler, and the air outlet of the second supercharger is connected to the exhaust gas emission system; the exhaust gas recirculation system is provided with a one-way valve, so that the gas at the air outlet of the cylinder group cannot flow out after entering the exhaust gas recirculation system; The master controller uses the following method: The master controller acquires the DOC inner loop temperature rise requirement, the DOC ignition temperature and the DOC upstream actual temperature, which are preset in the master controller and used as parameters for calculating the DOC ignition temperature difference; The master controller selects a ramp factor for the DOC inner loop temperature rise requirement to obtain a target DOC inner loop temperature rise requirement; The master controller performs a ramp calculation on the target DOC inner ring temperature rise requirement, the DOC ignition temperature and the actual temperature upstream of the DOC to obtain the ignition temperature difference; The master controller performs PI calculation on the light-off temperature difference through a PID algorithm to obtain a light-off temperature difference PI value, and the light-off temperature difference PI value is used to correct the light-off temperature difference of the DOC oxidation catalytic converter; The master controller calculates the first fuel injection amount and the intake air amount according to the light-off temperature difference PI value; The master controller controls the DOC temperature to rise according to the first fuel injection amount and the intake air amount until the DOC reaches the ignition temperature; After the DOC reaches the light-off temperature, the master controller acquires the downstream temperature of the DOC; The master controller calculates a first downstream temperature difference according to the downstream temperature of the DOC; The master controller calculates the first downstream temperature difference and the expected value of the oil injection amount to obtain a target downstream temperature difference; The master controller calculates the fuel injection amount according to the target downstream temperature difference to obtain a target fuel injection amount; The master controller calculates the first downstream temperature difference according to the downstream temperature of the DOC, including: The master controller calculates the temperature difference between the downstream temperature and the standard value of the downstream temperature to obtain a preliminary downstream temperature difference; The master controller corrects the preliminary downstream temperature difference according to the downstream temperature expectation value to obtain a first downstream temperature difference; The master controller calculates the fuel injection amount according to the target downstream temperature difference, and obtains the target fuel injection amount including: The master controller calculates the fuel injection amount according to the target downstream temperature difference to obtain a second fuel injection amount; The master controller obtains the feedback value of the DOC to obtain the required oil volume; The master controller determines whether the second fuel injection amount is less than the required fuel amount; If yes, the master controller determines the second fuel injection amount as the target fuel injection amount; If not, the master controller determines the required fuel quantity as the target fuel injection quantity.

2. The device according to claim 1, characterized in that The master controller includes a data acquisition system, a computer, an INCA calibration system and an ECU electronic control unit.

3. The device according to claim 2, characterized in that The data acquisition system will obtain the data required by the computer for temperature control calculations through the emission analyzer, the temperature sensor and the pressure difference sensor, and send the data to the computer after acquisition. The computer calculates the data collected by the data acquisition system and sends the calculation results to the INCA calibration system for data calibration, and sends the calibration results to the ECU, so that the ECU adjusts the temperature of the exhaust emission system according to the calibration results.

4. The device according to claim 1, characterized in that The master controller calculates the first fuel injection amount and the intake air amount according to the light-off temperature difference PI value, including: The master controller acquires a first fuel injection amount preset range and a first fuel injection amount minimum value; The master controller calculates the first fuel injection amount preset range and the first fuel injection amount minimum value according to the light-off temperature difference PI value to obtain the first fuel injection amount; The master controller obtains the air intake range and the minimum air intake value; The master controller calculates the intake air amount range and the minimum intake air amount according to the light-off temperature difference PI value to obtain the intake air amount.

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