DPF efficiency monitoring method and device and engine system

Abstract

The invention discloses a DPF efficiency monitoring method and device and an engine system, and relates to the technical field of DPFs. The DPF efficiency monitoring method comprises the steps that the rotating speed and the exhaust flow of an engine in the current period and the differential pressure value of the DPF are determined, and the DPF is connected with the engine; determining a current operation sub-region of the engine based on the rotating speed and the exhaust flow of the current period; determining a DPF pressure difference limit value corresponding to the current operation sub-region based on the current operation sub-region and a corresponding relation between the operation sub-region and the DPF pressure difference limit value; and if the pressure difference value of the DPF in the current period is smaller than the DPF pressure difference limiting value corresponding to the current operation subarea, it is judged that the efficiency of the DPF is low. According to the DPF efficiency monitoring method and device, the operation area of the engine is divided more finely based on the rotating speed range and the exhaust flow range of the engine, the DPF efficiency operation working conditions of the engine in different operation sub-areas can be monitored, and the accuracy and timeliness of DPF efficiency monitoring are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of DPF, and in particular to a method and equipment for monitoring the efficiency of a DPF and an engine system. Background Art

[0002] The pollution of diesel engines mainly comes from three aspects: particulate matter (PM), hydrocarbons (HCx), and nitrogen oxides (NOx). In order to reduce the emission of particulate matter, DPF (Diesel Particulate Filter) is currently used to treat particulate matter. DPF can reduce the emission of particulate matter generated by the engine by at least 90% by burning the captured particulate matter during the operation of the vehicle. When the diesel engine discharges exhaust gas containing particulate matter, the exhaust gas will enter the DPF through a special pipeline, and pass through the densely arranged bag filter inside it, and adsorb the particulate matter on the bag filter made of metal fiber felt; when the adsorption amount of particulate matter reaches a certain level, the particulate matter adsorbed on it will be burned through the process of active regeneration and passive regeneration, and turned into harmless carbon dioxide for discharge. However, when the capture performance of DPF decreases or does not work, that is, when the efficiency of DPF decreases, the particulate matter in the exhaust gas will exceed the standard, resulting in a decrease in air quality, affecting human health and environmental protection, and failing to meet regulatory requirements.

[0003] At present, a differential pressure sensor is usually set at the input and output ends of the DPF to monitor the efficiency of the DPF through the pressure difference between the input and output ends of the DPF. However, this method can only monitor the operating area of ​​the engine with a high exhaust flow rate and cannot provide accurate and real-time alarms. Summary of the invention

[0004] The object of the present invention is to provide a method, device and engine system for monitoring the efficiency of DPF, which can make a more detailed division of the operating area of ​​the engine based on the engine speed range and the exhaust flow range, so that the operating conditions of the DPF efficiency of the engine in different operating sub-areas can be monitored subsequently, thereby improving the accuracy and timeliness of the monitoring of the efficiency of DPF.

[0005] In a first aspect, the present application discloses a method for monitoring the efficiency of a DPF, comprising:

[0006] Determining the speed of the engine, the exhaust flow rate, and the pressure difference value of the DPF in the current cycle, the DPF being connected to the engine;

[0007] Determining a current operating sub-region of the engine based on the speed and exhaust flow rate of the current cycle, wherein the operating region of the engine is divided into at least two operating sub-regions based on the speed range and exhaust flow rate range of the engine, and the exhaust flow rate range is divided into at least two exhaust flow rate intervals;

[0008] Determining the DPF pressure difference limit value corresponding to the current operating sub-region based on the current operating sub-region and the corresponding relationship between the operating sub-region and the DPF pressure difference limit value;

[0009] If the DPF pressure difference value of the current cycle is less than the DPF pressure difference limit value corresponding to the current operation sub-region, it is determined that the efficiency of the DPF is low.

[0010] Optionally, after determining the DPF pressure difference limit value corresponding to the current operating sub-region based on the current operating sub-region and the correspondence between the operating sub-region and the DPF pressure difference limit value, the method further includes:

[0011] Obtaining a basic pressure difference value of the DPF when the engine is not running;

[0012] Subtracting the DPF pressure difference value from a base pressure difference value of the DPF when the engine is not running to obtain a corrected DPF pressure difference value;

[0013] Correspondingly, if the pressure difference value of the DPF in the current cycle is less than the DPF pressure difference limit value corresponding to the current operation sub-area, it is determined that the efficiency of the DPF is low, including:

[0014] If the corrected DPF pressure difference value of the current cycle is less than the DPF pressure difference limit value corresponding to the current operation sub-region, it is determined that the efficiency of the DPF is low.

[0015] Optionally, the process of determining the correspondence between the operating sub-area and the DPF pressure difference limit is as follows:

[0016] Determine a first DPF differential pressure limit value of a normal DPF in each operating sub-area;

[0017] Determine a second DPF differential pressure limit value in each operating sub-region of the DPF with reduced efficiency;

[0018] For any operation sub-region, determining a DPF pressure difference limit value of the operation sub-region, wherein the DPF pressure difference limit value is less than a first DPF pressure difference limit value corresponding to the operation sub-region and is greater than a second DPF pressure difference limit value corresponding to the operation sub-region;

[0019] A corresponding relationship between the operating sub-areas and the DPF pressure difference limit values ​​is established based on the DPF pressure difference limit values ​​of the operating sub-areas.

[0020] Optionally, determining a first DPF pressure difference limit value of a normal DPF in each operating sub-area includes:

[0021] For a normal DPF, a universal characteristic scan is performed according to each operating sub-area to obtain a first DPF pressure difference limit value of the normal DPF in each operating sub-area;

[0022] Determine the second DPF pressure difference limit value of the DPF with reduced efficiency in each operating sub-area, including:

[0023] For the DPF with reduced efficiency, a universal characteristic sweep is performed according to each operating sub-region to obtain a second DPF pressure difference limit value of the DPF with reduced efficiency in each operating sub-region.

[0024] Optionally, the speed range is divided into at least two speed intervals.

[0025] Optionally, after determining that the efficiency of the DPF is low, the method further includes:

[0026] Control the alarm module to issue an alarm message indicating low efficiency of the DPF;

[0027] and / or,

[0028] A torque limit command is sent to an ECU of a vehicle where the engine is located.

[0029] Optionally, if the DPF pressure difference value of the current cycle is less than the DPF pressure difference limit value corresponding to the current operation sub-area, the method further includes:

[0030] Determining a weight coefficient of the current operating sub-region, wherein the weight coefficient is positively correlated with a rotation speed and an exhaust flow rate corresponding to the current operating sub-region;

[0031] Determine the duration of time during which the DPF pressure difference value is less than the DPF pressure difference limit value corresponding to the current operating sub-area in the current cycle;

[0032] Determine an efficiency contribution value of the current operating sub-region based on the weight coefficient of the current operating sub-region and the duration, wherein the efficiency contribution value is positively correlated with the weight coefficient of the current operating sub-region and the duration, respectively;

[0033] Calculating the sum of the efficiency contribution value of the current operating sub-region and the total efficiency contribution value of the previous cycle up to the current cycle, and using the sum as the total efficiency contribution value up to the current cycle;

[0034] When the total efficiency contribution value of the current cycle is greater than the preset error limit value, the step of determining whether the efficiency of the DPF is low is entered.

[0035] Optionally, determining the efficiency contribution value of the current operating sub-region based on the weight coefficient of the current operating sub-region and the duration includes:

[0036] The product of the weight coefficient of the current operating sub-region and the duration is used as the efficiency contribution value of the current operating sub-region.

[0037] In a second aspect, the present application discloses a DPF efficiency monitoring device, comprising:

[0038] Memory, used to store computer programs;

[0039] The processor is used to execute the computer program to implement the steps of the method for monitoring the efficiency of the DPF as described above.

[0040] In a third aspect, the present application discloses an engine system, comprising an engine, a DPF, a pressure differential sensor, and also comprising a monitoring device for the efficiency of the DPF as described above, wherein the engine is connected to the DPF, the pressure differential sensor is connected to the DPF, and the monitoring device for the efficiency of the DPF is respectively connected to the engine and the pressure differential sensor.

[0041] The present application discloses a method, device and engine system for monitoring the efficiency of a DPF. First, the engine's operating area is divided into at least two operating sub-areas using the engine's speed range and exhaust flow range in advance, and the exhaust flow range is divided into at least two exhaust flow intervals. After the engine's current cycle speed, exhaust flow and DPF pressure difference value are determined, the engine's current operating sub-area is determined by the current cycle speed and exhaust flow, and then the DPF pressure difference limit corresponding to the current operating sub-area is determined according to the current operating sub-area and the corresponding relationship between the operating sub-area and the DPF pressure difference limit value. If the DPF pressure difference value of the current cycle is less than the DPF pressure difference limit value corresponding to the current operating sub-area, the DPF efficiency is determined to be low. It can be seen that the present application divides the engine's operating area more finely based on the engine's speed range and exhaust flow range, and the exhaust flow range is divided into at least two exhaust flow intervals, so that the engine's operating conditions of the efficiency of the DPF in different operating sub-areas can be monitored later, which improves the accuracy and timeliness of the monitoring of the efficiency of the DPF. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the prior art and the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0043] Figure 1 It is a flow chart of a method for monitoring the efficiency of a DPF disclosed in the present invention;

[0044] Figure 2 The present invention is a structural diagram of an electronic device disclosed in the present invention. DETAILED DESCRIPTION

[0045] The core of the present invention is to provide a method, device and engine system for monitoring the efficiency of DPF, which can divide the operating area of ​​the engine more finely based on the engine speed range and exhaust flow range, so that the operating conditions of the DPF efficiency of the engine in different operating sub-areas can be monitored subsequently, thereby improving the accuracy and timeliness of the monitoring of the efficiency of DPF.

[0046] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. 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 are within the scope of protection of the present invention.

[0047] At present, a pressure difference sensor is usually set for the DPF, and the efficiency of the DPF is monitored by measuring the pressure difference between the inlet and outlet of the DPF. However, this method can only monitor the operating area of ​​the engine with a high exhaust flow rate, and cannot provide accurate and real-time alarms. To this end, the present application provides a DPF efficiency monitoring solution to monitor the operating conditions of the DPF efficiency of the engine in different operating sub-areas, thereby improving the accuracy and timeliness of the monitoring of the DPF efficiency.

[0048] See also Figure 1 As shown, Figure 1 The present invention is a flowchart of a method for monitoring the efficiency of a DPF.

[0049] The method for monitoring the efficiency of the DPF comprises:

[0050] S11, determining the speed, exhaust flow rate and pressure difference value of the DPF of the current cycle of the engine, and the DPF is connected to the engine;

[0051] S12, determining a current operating sub-region of the engine based on the speed and exhaust flow rate of the current cycle, wherein the operating region of the engine is divided into at least two operating sub-regions based on the speed range and exhaust flow rate range of the engine, and the exhaust flow rate range is divided into at least two exhaust flow rate intervals;

[0052] In this embodiment, in order to divide the operation sub-areas of the engine more finely, compared with the prior art that divides the operation sub-areas of the engine only based on the exhaust flow rate of the engine, the present application divides the operation sub-areas of the engine based on the speed and exhaust flow rate of the current cycle of the engine. It should be noted that the changes in the speed and exhaust flow rate of the current cycle of the engine have a greater impact on the pressure difference value of the DPF. When the speed of the current cycle of the engine is constant, the greater the exhaust flow rate of the current cycle of the engine, the greater the pressure difference value of the DPF of the current cycle; when the exhaust flow rate of the current cycle of the engine is constant, the greater the speed of the current cycle of the engine, the greater the pressure difference value of the DPF of the current cycle.

[0053] Based on this, the present application pre-constructs the engine operation area based on the engine speed and exhaust flow rate of the current cycle, and divides the operation area to obtain various operation sub-areas. For example, the engine operation sub-areas can be divided according to the exhaust flow interval of each kg / h and the speed interval of each 200r / min. Please refer to Table 1, which is a table of various operation sub-areas determined based on the engine speed range and exhaust flow range disclosed in the present invention:

[0054] Table 1 The operating sub-regions determined based on the engine speed range and exhaust flow range

[0055]

[0056] Specifically, the DPF is connected to the engine. During the process of the DPF continuously capturing and processing the particulate emission substances emitted by the engine, the pressure difference value between the inlet and outlet of the DPF is continuously collected by the pressure difference sensor, so as to determine the pressure difference value of the DPF in the current cycle of the engine in real time, and at the same time continuously determine the current operating sub-area of ​​the engine based on the rotation speed and exhaust flow of the current cycle.

[0057] S13, determining the DPF pressure difference limit value corresponding to the current operating sub-region based on the current operating sub-region and the corresponding relationship between the operating sub-region and the DPF pressure difference limit value;

[0058] In this embodiment, since the operation area of ​​the engine is divided into at least two operation sub-areas based on the engine speed range and the exhaust flow range, and the current operation sub-area of ​​the engine is determined based on the speed and exhaust flow of the current cycle, the DPF pressure difference limit corresponding to the current operation sub-area can be determined based on the current operation sub-area and the corresponding relationship between the operation sub-area and the DPF pressure difference limit, that is, the DPF pressure difference limit corresponding to the current operation sub-area is determined based on the corresponding relationship between the speed and exhaust flow of the current cycle and the DPF pressure difference limit. Because the changes in the engine speed and exhaust flow have a greater impact on the DPF pressure difference value, when the speed of the current cycle of the engine is constant, if the exhaust flow of the current cycle of the engine is greater, the pressure difference value of the DPF in the current cycle is greater, and accordingly, the DPF pressure difference limit corresponding to the current operation sub-area is also greater; when the exhaust flow of the current cycle of the engine is constant, if the speed of the current cycle of the engine is greater, the pressure difference value of the DPF in the current cycle is greater, and accordingly, the DPF pressure difference limit corresponding to the current operation sub-area is also greater.

[0059] S14. If the DPF pressure difference value of the current cycle is less than the DPF pressure difference limit value corresponding to the current operation sub-region, it is determined that the efficiency of the DPF is low.

[0060] In this embodiment, if the pressure difference value of the DPF in the current cycle is less than the DPF pressure difference limit value corresponding to the current operating sub-area, it indicates that the capture and / or treatment performance of the DPF is reduced, which will cause the particulate emission in the exhaust gas to exceed the standard and cause the air quality to deteriorate, and the efficiency of the DPF is determined to be low.

[0061] It can be seen that the present application makes a more detailed division of the engine's operating area based on the engine speed range and the exhaust flow range, and the exhaust flow range is divided into at least two exhaust flow intervals, so that the operating conditions of the engine's DPF efficiency in different operating sub-areas can be monitored subsequently, thereby improving the accuracy and timeliness of the DPF efficiency monitoring.

[0062] Based on the above embodiments:

[0063] As an optional embodiment, after determining the DPF pressure difference limit value corresponding to the current operating sub-region based on the current operating sub-region and the corresponding relationship between the operating sub-region and the DPF pressure difference limit value, the method further includes:

[0064] Obtain the basic pressure difference value of the DPF when the engine is not running;

[0065] Subtract the DPF pressure difference value from the base pressure difference value of the DPF when the engine is not running to obtain a corrected DPF pressure difference value;

[0066] Correspondingly, if the DPF pressure difference value of the current cycle is less than the DPF pressure difference limit value corresponding to the current operating sub-area, it is determined that the efficiency of the DPF is low, including:

[0067] If the corrected DPF pressure difference value of the current cycle is less than the DPF pressure difference limit value corresponding to the current operating sub-region, it is determined that the efficiency of the DPF is low.

[0068] Specifically, this embodiment uses a differential pressure sensor to monitor the differential pressure value of the DPF in the current cycle. However, the differential pressure sensor may have a problem of differential pressure drift. Even if the DPF is not working and there is no pressure difference between the two ends of the DPF, the differential pressure value output by the differential pressure sensor is not 0. The differential pressure drift of the differential pressure sensor will cause the differential pressure value of the DPF in the current cycle to be too large. In the process of determining whether the differential pressure value of the DPF in the current cycle is less than the differential pressure limit value of the DPF corresponding to the current operating sub-area, an error in judgment may occur, thereby causing an erroneous judgment on the efficiency of the DPF. In addition, aging or damage of the differential pressure sensor may also cause the differential pressure value of the DPF in the current cycle to be inaccurate.

[0069] Taking into account the errors existing in the DPF itself, in order to more accurately monitor the pressure differential value of the DPF and improve the monitoring efficiency of the DPF, it is necessary to perform pressure differential self-learning to correct the pressure differential value of the DPF directly obtained by the pressure differential sensor. Specifically, it is necessary to obtain in advance the basic pressure differential value of the DPF when the engine is not running, and to subtract the pressure differential value of the DPF from the basic pressure differential value of the DPF when the engine is not running to obtain the corrected pressure differential value of the DPF. Taking these sources of error into consideration, the actual pressure differential value of the DPF after correction is determined, and the actual pressure differential value of the current cycle is judged with the DPF pressure differential limit corresponding to the current operating sub-area, eliminating the interference of the errors existing in the DPF itself, so as to achieve an accurate judgment of the efficiency of the DPF.

[0070] It can be seen that the present application performs self-learning correction on the DPF pressure difference value during the process of monitoring the DPF efficiency, thereby eliminating the interference caused by the problems existing in the DPF itself on the DPF pressure difference value of the current cycle, and improving the accuracy of the judgment on whether the corrected DPF pressure difference value of the current cycle is less than the DPF pressure difference limit value corresponding to the current operating sub-area, thereby achieving the accuracy of DPF efficiency monitoring and reducing error reporting.

[0071] As an optional embodiment, the process of determining the correspondence between the operating sub-area and the DPF pressure difference limit is as follows:

[0072] Determine a first DPF differential pressure limit value of a normal DPF in each operating sub-area;

[0073] Determine a second DPF differential pressure limit value in each operating sub-region of the DPF with reduced efficiency;

[0074] For any operation sub-region, determining a DPF pressure difference limit value of the operation sub-region, wherein the DPF pressure difference limit value is less than a first DPF pressure difference limit value corresponding to the operation sub-region and is greater than a second DPF pressure difference limit value corresponding to the operation sub-region;

[0075] A corresponding relationship between the operating sub-region and the DPF pressure difference limit value is established based on the DPF pressure difference limit value of each operating sub-region.

[0076] In this embodiment, in order to obtain the DPF pressure difference limit value corresponding to the current operating sub-area, the corresponding relationship between the operating sub-area and the DPF pressure difference limit value can be used to compare with the current operating sub-area, and the DPF pressure difference limit value of the operating sub-area with the consistent comparison result is used as the DPF pressure difference limit value corresponding to the current operating sub-area. Therefore, it is necessary to predetermine the corresponding relationship between the operating sub-area and the DPF pressure difference limit value. Specifically, the normal DPF can be pre-connected to the engine to determine the first DPF pressure difference limit value of the normal DPF in each operating sub-area; similarly, the DPF with reduced efficiency can be pre-connected to the engine to determine the second DPF pressure difference limit value of the DPF with reduced efficiency in each operating sub-area. The pressure difference limit value is less than the first DPF pressure difference limit value corresponding to the operating sub-area and greater than the second DPF pressure difference limit value corresponding to the operating sub-area as the DPF pressure difference limit value. For example, the arithmetic mean of the first DPF pressure difference limit value and the second DPF pressure difference limit value can be used as the DPF pressure difference limit value.

[0077] It should be noted that the capture performance and treatment process of the DPF need to be carried out within a specific pressure difference range. If the pressure difference is too low, it may mean that the capture efficiency of the DPF is reduced and the particulate matter cannot be effectively filtered; while a too high pressure difference may cause excessive wear or damage to the DPF. Therefore, it is necessary to set the DPF pressure difference limit value to be less than the first DPF pressure difference limit value corresponding to the operating sub-area and greater than the second DPF pressure difference limit value corresponding to the operating sub-area. Setting a pressure difference limit value between these two limit values ​​can ensure that the DPF works efficiently while avoiding potential damage caused by excessive pressure difference.

[0078] It can be seen that selecting an appropriate pressure difference limit can improve the reliability of DPF efficiency monitoring while ensuring the performance of DPF.

[0079] As an optional embodiment, determining a first DPF pressure difference limit value of a normal DPF in each operating sub-area includes:

[0080] For a normal DPF, a universal characteristic scan is performed according to each operating sub-area to obtain a first DPF pressure difference limit value of the normal DPF in each operating sub-area;

[0081] Determine the second DPF pressure difference limit value of the DPF with reduced efficiency in each operating sub-area, including:

[0082] For the DPF with reduced efficiency, a universal characteristic sweep is performed according to each operating sub-region to obtain a second DPF pressure difference limit value of the DPF with reduced efficiency in each operating sub-region.

[0083] Specifically, since the operating area of ​​the engine is divided into at least two operating sub-areas based on the engine speed range and exhaust flow range, and the relationship between the engine speed range and exhaust flow range and the pressure difference value of the DPF can be represented by a universal characteristic. The universal characteristic curve can fully reflect the comprehensive performance of the engine at different speeds and exhaust flows, including the pressure difference value of the DPF, etc., and can better understand the performance of the engine under different operating conditions. The present application pre-connects a normal DPF to the engine, obtains at least two operating sub-areas in the same way as the engine's operating area is divided, and performs a universal characteristic sweep on each operating sub-area to obtain the first DPF pressure difference limit of the normal DPF in each operating sub-area; similarly, pre-connects a DPF with reduced efficiency to the engine, obtains at least two operating sub-areas in the same way as the engine's operating area is divided, and performs a universal characteristic sweep on each operating sub-area to obtain the first DPF pressure difference limit of the DPF with reduced efficiency in each operating sub-area.

[0084] It can be seen that for both the normal DPF and the DPF with reduced efficiency, the universal characteristic scanning points are performed according to each operating sub-area, and the pressure difference limit value corresponding to each operating sub-area can be determined more accurately.

[0085] As an optional embodiment, the rotation speed range is divided into at least two rotation speed intervals.

[0086] In order to correctly monitor the efficiency of the DPF when the engine is in various operating conditions, the present embodiment divides the engine's operating area into at least two speed intervals while also dividing the engine's speed range into at least two speed intervals based on different exhaust flow rates. Because the correspondence between the engine's speed range and the DPF pressure difference value is relatively obvious, the speed range is divided into at least two speed intervals, and the engine's operating area is more finely divided in at least two exhaust flow intervals. Subsequently, the operating conditions of the engine's DPF efficiency in different operating sub-areas can be monitored, thereby improving the accuracy and timeliness of the DPF efficiency monitoring.

[0087] It can be seen that by dividing the speed range into at least two speed intervals, the performance of the DPF under different working conditions can be more accurately evaluated, and the performance changes of the DPF can be better understood and predicted, thereby improving the accuracy and timeliness of the monitoring of the DPF efficiency.

[0088] As an optional embodiment, after determining that the efficiency of the DPF is low, the method further includes:

[0089] Control the alarm module to issue an alarm message indicating low efficiency of the DPF;

[0090] and / or,

[0091] Send a torque limit command to the ECU of the vehicle where the engine is located.

[0092] In this embodiment, in order to improve the safety of DPF efficiency monitoring, after obtaining the result of low DPF efficiency, the alarm module can be controlled to issue an alarm message of low DPF efficiency and / or send a torque limit command to the ECU of the vehicle where the engine is located, so as to issue a reminder and / or the ECU controls the torque output of the engine to prevent emissions from exceeding the standard.

[0093] It can be seen that after determining that the DPF efficiency is low, taking measures such as controlling the alarm module to issue an alarm message of low DPF efficiency and / or sending a torque limit command to the ECU of the vehicle where the engine is located improves the safety of monitoring the DPF efficiency.

[0094] As an optional embodiment, if the DPF pressure difference value of the current cycle is less than the DPF pressure difference limit value corresponding to the current operating sub-area, the method further includes:

[0095] Determine a weight coefficient of the current operating sub-region, where the weight coefficient is positively correlated with the speed and exhaust flow rate corresponding to the current operating sub-region;

[0096] Determine the duration of the DPF pressure difference value in the current cycle being less than the DPF pressure difference limit value corresponding to the current operating sub-area;

[0097] Determine the efficiency contribution value of the current operating sub-region based on the weight coefficient and the duration of the current operating sub-region, and the efficiency contribution value is positively correlated with the weight coefficient and the duration of the current operating sub-region respectively;

[0098] Calculate the sum of the efficiency contribution value of the current operating sub-region and the total efficiency contribution value of the previous cycle up to the current cycle, and use the sum as the total efficiency contribution value up to the current cycle;

[0099] When the total efficiency contribution value of the current cycle is greater than the preset error limit value, the step of determining whether the efficiency of the DPF is low is entered.

[0100] Considering that if the speed and / or exhaust flow rate of the current cycle of the generator is relatively low, correspondingly, the pressure difference value of the DPF of the current cycle obtained based on the relatively low speed and / or exhaust flow rate of the current cycle will also be relatively small, and usually the accuracy of the pressure difference value collected by the pressure difference sensor with a small value is lower than the accuracy of the pressure difference value collected with a slightly larger value. In order to improve the detection accuracy of the DPF efficiency, a weight coefficient is set for each operating sub-area. In addition, the duration of the pressure difference value of the DPF of the current cycle being less than the corresponding pressure difference limit value can also characterize the efficiency of the DPF. Therefore, the present application also considers the duration of the pressure difference value of the DPF of the current cycle being less than the corresponding pressure difference limit value.

[0101] Specifically, after the pressure difference value of the DPF in the current cycle is less than the pressure difference limit value of the DPF corresponding to the current operating sub-region, the present embodiment uses the weight coefficient and the duration of the current operating sub-region to determine the efficiency contribution value of the current operating sub-region. Among them, the speed and exhaust flow of the divided engine are both positively correlated with the weight coefficient. When the speed of the current operating sub-region is constant, the larger the exhaust flow of the current operating sub-region, the larger the corresponding weight coefficient of the current operating sub-region; when the exhaust flow of the current operating sub-region is constant, the larger the speed of the current operating sub-region, the larger the corresponding weight coefficient of the current operating sub-region. Then, the efficiency contribution value of the current operating sub-region is added to the total efficiency contribution value of the previous cycle up to the current cycle, to further determine whether the pressure difference value of the DPF in the current cycle is less than the pressure difference limit value of the DPF corresponding to the current operating sub-region due to the low efficiency of the DPF.

[0102] Specifically, the efficiency contribution value of the current operating sub-area is determined based on the weight coefficient and duration of the current operating sub-area, the contribution degree of the current operating sub-area to the overall efficiency is obtained, and the efficiency contribution value of the current operating sub-area is added to the total efficiency contribution value of the previous cycle up to the current cycle to obtain the total efficiency contribution value of the current cycle, and then it is determined whether the total efficiency contribution value of the current cycle is greater than the preset error limit value. If the total efficiency contribution value of the current cycle is greater than the preset error limit value, it indicates that the efficiency of the DPF is low, and the step of determining the low efficiency of the DPF is entered.

[0103] In addition, when the duration of the current operating sub-area is constant, the greater the weight coefficient of the current operating sub-area, the greater the efficiency contribution value of the current operating sub-area; when the duration weight coefficient of the current operating sub-area is constant, the longer the duration of the current operating sub-area, the greater the efficiency contribution value of the current operating sub-area.

[0104] It can be seen that the efficiency of the DPF operating sub-areas at different speeds and different scheduled flow rates is different, and different weight coefficients need to be assigned to the operating sub-areas at different speeds and different scheduled flow rates. When further determining whether the pressure difference value of the DPF in the current cycle is less than the DPF pressure difference limit value corresponding to the current operating sub-area due to the low efficiency of the DPF, the different degrees of influence of each operating sub-area on the efficiency of the DPF are taken into consideration in parallel, thereby improving the accuracy of monitoring the efficiency of the DPF.

[0105] As an optional embodiment, determining the efficiency contribution value of the current operating sub-region based on the weight coefficient and the duration of the current operating sub-region includes:

[0106] The product of the weight coefficient of the current operating sub-region and the duration is taken as the efficiency contribution value of the current operating sub-region.

[0107] The product of the weight coefficient of the current running sub-area and the duration

[0108] The weight coefficient can be used to indicate the contribution of the current operating sub-region to the overall efficiency among all operating sub-regions, and the duration of the DPF pressure difference value in the current cycle being less than the DPF pressure difference limit value corresponding to the current operating sub-region can reflect the length of time that the efficiency of the current operating sub-region is low in the current cycle. By taking the product of these two factors as the efficiency contribution value of the current operating sub-region, the contribution degree of the current operating sub-region and its actual usage can be comprehensively considered, thereby more accurately evaluating the contribution of the current operating sub-region to the overall performance of the system.

[0109] It can be seen that using the product of the weight coefficient of the current operating sub-area and the duration as the efficiency contribution value of the current operating sub-area can help make a more accurate judgment in the process of whether the efficiency of the DPF is low, thereby improving the accuracy of monitoring the efficiency of the DPF.

[0110] The present application also provides an engine system, including an engine, a DPF, a pressure difference sensor, and also includes a monitoring device for the efficiency of the DPF as described above, the engine is connected to the DPF, the pressure difference sensor is connected to the DPF, and the DPF efficiency monitoring device is respectively connected to the engine and the pressure difference sensor.

[0111] In this embodiment, the differential pressure sensor is used to measure the differential pressure value between the inlet and outlet of the DPF. By monitoring the differential pressure value between the inlet and outlet of the DPF, the accumulation of particulate matter inside the DPF can be determined, thereby evaluating the filtration efficiency of the DPF. Specifically, when the particulate matter inside the DPF gradually increases, the exhaust flow will be blocked, thereby causing an increase in the differential pressure. The differential pressure sensor can monitor this differential pressure change in real time, and determine whether the efficiency of the DPF is low based on the real-time differential pressure data, so as to take corresponding measures to ensure the normal operation of each device.

[0112] It can be seen that the present application makes a more detailed division of the engine's operating area based on the engine speed range and the exhaust flow range, and the exhaust flow range is divided into at least two exhaust flow intervals, so that the operating conditions of the engine's DPF efficiency in different operating sub-areas can be monitored subsequently, thereby improving the accuracy and timeliness of the DPF efficiency monitoring.

[0113] Furthermore, the present application also discloses an electronic device. Figure 2 This is a structural diagram of an electronic device disclosed in the present invention, and the content in the diagram cannot be regarded as any limitation on the scope of use of this application. The electronic device 20 may specifically include: at least one processor 21, at least one memory 22, a power supply 23, a communication interface 24, an input / output interface 25, and a communication bus 26. The memory 22 is used to store a computer program, which is loaded and executed by the processor 21 to implement the relevant steps in the DC voltage control of the inverter disclosed in any of the aforementioned embodiments. In addition, the electronic device 20 in this embodiment may specifically be an electronic computer.

[0114] In this embodiment, the power supply 23 is used to provide working voltage for each hardware device on the electronic device 20; the communication interface 24 can create a data transmission channel between the electronic device 20 and the external device, and the communication protocol it follows is any communication protocol that can be applied to the technical solution of the present application, and is not specifically limited here; the input and output interface 25 is used to obtain external input data or output data to the outside world, and its specific interface type can be selected according to specific application needs and is not specifically limited here.

[0115] In addition, the memory 22, as a carrier for storing resources, can be a read-only memory, a random access memory, a disk or an optical disk, etc. The resources stored thereon can include an operating system 221, a computer program 222, etc., and the storage method can be temporary storage or permanent storage.

[0116] The operating system 221 is used to manage and control the hardware devices and computer program 222 on the electronic device 20, and can be Windows Server, Unix, Linux, etc. In addition to the computer program that can be used to complete the DC voltage control of the inverter performed by the electronic device 20 disclosed in any of the aforementioned embodiments, the computer program 222 can further include a computer program that can be used to complete other specific tasks.

[0117] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0118] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0119] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for monitoring the efficiency of a DPF, characterized in that: include: Determining the speed of the engine, the exhaust flow rate, and the pressure difference value of the DPF in the current cycle, the DPF being connected to the engine; Determining a current operating sub-region of the engine based on the speed and exhaust flow rate of the current cycle, wherein the operating region of the engine is divided into at least two operating sub-regions based on the speed range and exhaust flow rate range of the engine, and the exhaust flow rate range is divided into at least two exhaust flow rate intervals; Determining the DPF pressure difference limit value corresponding to the current operating sub-region based on the current operating sub-region and the corresponding relationship between the operating sub-region and the DPF pressure difference limit value; If the DPF pressure difference value of the current cycle is less than the DPF pressure difference limit value corresponding to the current operation sub-region, it is determined that the efficiency of the DPF is low.

2. The method for monitoring the efficiency of a DPF according to claim 1, characterized in that: After determining the DPF pressure difference limit value corresponding to the current operating sub-region based on the current operating sub-region and the corresponding relationship between the operating sub-region and the DPF pressure difference limit value, the method further includes: Obtaining a basic pressure difference value of the DPF when the engine is not running; Subtracting the DPF pressure difference value from a base pressure difference value of the DPF when the engine is not running to obtain a corrected DPF pressure difference value; Correspondingly, if the pressure difference value of the DPF in the current cycle is less than the DPF pressure difference limit value corresponding to the current operation sub-area, it is determined that the efficiency of the DPF is low, including: If the corrected DPF pressure difference value of the current cycle is less than the DPF pressure difference limit value corresponding to the current operation sub-region, it is determined that the efficiency of the DPF is low.

3. The method for monitoring the efficiency of a DPF according to claim 1, characterized in that: The process of determining the corresponding relationship between the operating sub-area and the DPF pressure difference limit is as follows: Determine a first DPF differential pressure limit value of a normal DPF in each operating sub-area; Determine a second DPF differential pressure limit value of the DPF with reduced efficiency in each operating sub-region; For any operation sub-region, determining a DPF pressure difference limit value of the operation sub-region, wherein the DPF pressure difference limit value is less than a first DPF pressure difference limit value corresponding to the operation sub-region and is greater than a second DPF pressure difference limit value corresponding to the operation sub-region; A corresponding relationship between the operating sub-areas and the DPF pressure difference limit values ​​is established based on the DPF pressure difference limit values ​​of the operating sub-areas.

4. The method for monitoring the efficiency of a DPF as claimed in claim 3, characterized in that: Determine the first DPF pressure difference limit of a normal DPF in each operating sub-area, including: For a normal DPF, a universal characteristic scan is performed according to each operating sub-area to obtain a first DPF pressure difference limit value of the normal DPF in each operating sub-area; Determine the second DPF pressure difference limit value of the DPF with reduced efficiency in each operating sub-area, including: For the DPF with reduced efficiency, a universal characteristic sweep is performed according to each operating sub-region to obtain a second DPF pressure difference limit value of the DPF with reduced efficiency in each operating sub-region.

5. The method for monitoring the efficiency of a DPF according to claim 1, characterized in that: The rotation speed range is divided into at least two rotation speed intervals.

6. The method for monitoring the efficiency of a DPF according to claim 1, characterized in that: After determining that the DPF efficiency is low, it also includes: Control the alarm module to issue an alarm message indicating low efficiency of the DPF; and / or, A torque limit command is sent to an ECU of a vehicle where the engine is located.

7. The method for monitoring the efficiency of a DPF according to any one of claims 1 to 6, characterized in that: If the DPF pressure difference value of the current cycle is less than the DPF pressure difference limit value corresponding to the current operation sub-area, the method further includes: Determining a weight coefficient of the current operating sub-region, wherein the weight coefficient is positively correlated with a rotation speed and an exhaust flow rate corresponding to the current operating sub-region; Determine the duration of time during which the DPF pressure difference value is less than the DPF pressure difference limit value corresponding to the current operating sub-area in the current cycle; Determine an efficiency contribution value of the current operating sub-region based on the weight coefficient of the current operating sub-region and the duration, wherein the efficiency contribution value is positively correlated with the weight coefficient of the current operating sub-region and the duration, respectively; Calculating the sum of the efficiency contribution value of the current operating sub-region and the total efficiency contribution value of the previous cycle up to the current cycle, and using the sum as the total efficiency contribution value up to the current cycle; When the total efficiency contribution value of the current cycle is greater than the preset error limit value, the step of determining whether the efficiency of the DPF is low is entered.

8. The method for monitoring the efficiency of a DPF as claimed in claim 7, characterized in that: Determining the efficiency contribution value of the current operating sub-region based on the weight coefficient of the current operating sub-region and the duration includes: The product of the weight coefficient of the current operating sub-region and the duration is used as the efficiency contribution value of the current operating sub-region.

9. A DPF efficiency monitoring device, characterized in that: include: Memory, used to store computer programs; A processor, configured to execute the computer program to implement the steps of the method for monitoring the efficiency of a DPF as claimed in any one of claims 1 to 8.

10. An engine system, characterized in that: It includes an engine, a DPF, a pressure difference sensor, and also includes a monitoring device for the efficiency of the DPF as described in claim 9, the engine is connected to the DPF, the pressure difference sensor is connected to the DPF, and the monitoring device for the efficiency of the DPF is respectively connected to the engine and the pressure difference sensor.

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