Egr flow online detection method, device, storage medium and apparatus of engine

Abstract

The application relates to an EGR flow online detection method, device, storage medium and apparatus of an engine. The method comprises the following steps: S100, simulating operation of the engine under N standard states, and acquiring simulation operation parameters of the engine under each standard state; N is an integer greater than or equal to 2, and at least one of the operation speed and the load of the engine under each standard state is different. S200, obtaining cooling medium heat absorption power W w标准 and exhaust heat dissipation power W e标准 under each standard state according to the simulation operation parameters of the engine under each standard state; obtaining correction coefficients delta 标准 between W w and W e under each standard state according to each W w标准 and each W e标准 ; S300, acquiring the operation speed and the load and online operation parameters of the engine under an online operation state; and S400, obtaining the EGR flow of the engine under the online operation state according to the correction coefficients under each standard state, the operation speed and the load and the online operation parameters of the engine under the online operation state.

Description

Technical Field

[0001] This application relates to the field of engine measurement and control technology, and in particular to a method, equipment, storage medium and device for online detection of EGR flow of an engine. Background Technology

[0002] In the field of engine technology, reducing engine emissions is a crucial research and development direction. Developing technologies and systems that can simultaneously reduce diesel particulate and nitrogen oxide (NOx) emissions is a major challenge in both the engine and environmental protection sectors. EGR (Exhaust Gas Recirculation) technology redirects a portion of the exhaust gas from the exhaust pipe back to the cylinders. Because the triatomic gases such as CO2, H2O, and NO2 in engine exhaust have high specific heat, the heat capacity increases when fresh air mixes with the exhaust gas. This increases the thermal power required to raise the temperature of the diluted exhaust gas by 1°C. In other words, with the total heat released by fuel combustion remaining constant, the engine's combustion temperature decreases, thus reducing NOx formation. Furthermore, the dilution effect of the exhaust gas on the fresh air lowers the oxygen concentration, further suppressing NOx formation.

[0003] EGR rate, or Exhaust Gas Recirculation, is the ratio of recirculated exhaust gas to the total intake air volume into the engine cylinders. It directly affects engine performance and NOx emissions, making EGR rate control crucial. The accuracy of EGR rate control is closely related to the accuracy of EGR flow measurement. Traditional technologies mostly use venturi tubes to measure exhaust gas flow; the smaller the cross-sectional area of ​​the venturi throat, the higher the measurement accuracy. However, a smaller throat increases flow resistance in the EGR pipeline, affecting exhaust gas intake and potentially causing the EGR rate to fall short of design requirements. Even if the EGR rate meets design requirements, it still increases energy consumption. In other words, traditional technologies face a trade-off between measurement accuracy and pipeline flow resistance when measuring EGR flow during engine operation.

[0004] Therefore, how to improve the accuracy of online detection of EGR flow under engine operating conditions without increasing the flow resistance of the EGR pipeline has become an urgent technical problem to be solved. Summary of the Invention

[0005] Therefore, it is necessary to provide an online EGR flow detection method, equipment, storage medium, and device that can improve the accuracy of EGR flow detection during engine operation without increasing the flow resistance of the EGR pipeline.

[0006] The first aspect of this application provides a method for online detection of EGR flow in an engine, comprising the following steps:

[0007] S100. Simulate engine operation under N standard conditions and obtain simulated operating parameters of the engine under each standard condition. These simulated operating parameters include the inlet temperature T of the cooling medium in the EGR cooler. 1标准 Cooling medium outlet temperature T 2标准 Exhaust gas inlet temperature T 3标准 Exhaust gas outlet temperature T 4标准 Cooling medium flow rate (m) w标准 EGR flow rate m e标准 and exhaust gas pressure P 标准 N is an integer ≥2, and at least one of the engine's operating speed and load is different under each standard condition;

[0008] S200. Based on the simulated operating parameters of the engine under each standard condition, obtain the cooling medium heat absorption power W under each standard condition. w标准 And exhaust gas heat dissipation power W e标准 According to the heat absorption power W of each cooling medium w标准 and the heat dissipation power of each exhaust gas W e标准 To obtain W under each standard state w标准 With the W e标准 The correction factor δ between 标准 ;

[0009] S300: Obtain the engine's operating speed and load, as well as online operating parameters, under online operating conditions. These online operating parameters include the EGR cooler's cooling medium inlet temperature T. 1运行 Cooling medium outlet temperature T 2运行 Exhaust gas inlet temperature T 3运行 Exhaust gas outlet temperature T 4运行 Cooling medium flow rate (m) w运行 and exhaust gas pressure P 运行 ;

[0010] S400. Based on the correction coefficients under each standard condition, the operating speed and load of the engine under online operating conditions, and the online operating parameters, the EGR flow rate of the engine under online operating conditions is obtained.

[0011] The above-described online EGR flow detection method simulates engine operation under N standard conditions and calculates the flow rate based on the T values ​​obtained under each standard condition. 1标准 T 2标准 T 3标准 T 4标准 m w标准 m e标准 and P 标准 Determine W under the corresponding standard state. w标准 With W e标准 Correction coefficients between them; then obtain the engine speed, load, and T under online operating conditions.1运行 T 2运行 T 3运行 T 4运行 and P 运行 Based on the above data under online operation conditions and combined with correction factors, the EGR flow m under this operation condition is determined. e运行 The above testing method eliminates the need for EGR flow testing using a venturi tube during engine operation, thus avoiding increased flow resistance in the EGR pipeline. Furthermore, besides the heat carried away by the cooling medium, some heat in the engine's EGR is lost through radiation and convection. This heat loss via radiation and convection is related to engine speed and load; therefore, a correction factor δ is used. 标准 It can correct W relatively accurately w标准 With W e标准 The relationship between them, and then based on the δ of the online operating status. 运行 To more accurately determine the EGR flow rate in the online operating state, and to improve the accuracy of the detection results by simulating the engine's operating state using N standard states.

[0012] In some embodiments, the operating speed and load of the N standard states are determined according to the following steps:

[0013] Select a different standard operating speeds;

[0014] b different standard loads are set at each operating speed;

[0015] Using a standard operating speed and a standard load as a set of standard state parameters, simulating the engine's operation under standard conditions means operating the engine under the standard state parameters.

[0016] Where N = a × b, and a and b are each independently selected from integers ≥ 1.

[0017] In some embodiments, the detection method satisfies at least one of the following (1) to (4):

[0018] (1) The magnitudes of the a different operating speeds are distributed by an equally spaced gradient;

[0019] (2) a is an integer ≥ 4;

[0020] (3) The magnitudes of the b different loads are distributed in an equally spaced gradient;

[0021] (4) b is an integer ≥ 4.

[0022] In some embodiments, S200 includes the following steps:

[0023] According to the T 1标准 The T 2标准 The m w标准 The W under the corresponding standard state is obtained by combining formula (1). w标准 ;

[0024] According to the T 3标准 The T 4标准 The m m标准 The W under the corresponding standard state is obtained by combining formula (2). e标准 ;

[0025] Calculate the δ according to formula (3) 标准 ;

[0026] Formulas (1) to (3) are as follows:

[0027] W w =C w ×m w ×(T2-T1) Formula (1),

[0028] W e =C e ×m e ×(T3-T4) Formula (2),

[0029] δ=W e / W w Formula (3),

[0030] In formulas (1) to (3), T1 is the inlet temperature of the cooling medium, T2 is the outlet temperature of the cooling medium, T3 is the inlet temperature of the exhaust gas, T4 is the outlet temperature of the exhaust gas, and C w For the specific heat capacity of the cooling medium, m w C represents the flow rate of the cooling medium. e For the specific heat capacity of the exhaust gas, m e This refers to the exhaust gas flow rate.

[0031] In some embodiments, the specific heat capacity C of the exhaust gas under various standard conditions is... e标准 Determine using the following steps:

[0032] According to the T 3标准 or T 4标准 and the P 标准 Determine the components of the exhaust gas and the molar content of each component under the corresponding standard conditions;

[0033] According to formula (4), C is obtained. e标准 ;

[0034] Formula (4) is as follows:

[0035] C e= a1×C1+……+a n-1 ×C n-1 +a n ×C n Formula (4),

[0036] a1 and C1 are the molar content and specific heat capacity of the first component in the exhaust gas, respectively. n-1 and C n-1 These represent the molar content and specific heat capacity of the (n-1)th component in the exhaust gas, respectively, a n and C n These represent the molar content and specific heat capacity of the nth component in the exhaust gas, respectively.

[0037] In some embodiments, S400 includes the following steps:

[0038] Based on the engine's operating speed and load under each standard condition, and the corresponding correction factor δ 标准 The speed and load under standard conditions and the correction factor δ are obtained. 标准 The relationship between them;

[0039] The engine's operating speed and load during online operation are interpolated into the correction relationship to obtain the corresponding correction coefficient δ. 运行 ;

[0040] According to the T 1运行 The T 2运行 Using the formula (1), the heat absorption power W of the cooling medium under online operating conditions is obtained. w运行 ;

[0041] According to the δ 运行 The W w运行 Using the formula (3), the exhaust gas heat dissipation power W under online operation is obtained. e运行 ;

[0042] According to the T 3运行 or the T mentioned 4运行 and the P 运行 The components and molar content of the exhaust gas under online operation conditions are determined, and C is obtained according to formula (4). e运行 ;

[0043] According to the W e运行 The C e运行 The T 3运行 The T 4运行 Using formula (2), the EGR flow rate m of the operating state is obtained. e运行 .

[0044] In some embodiments, the P 标准P is the inlet or outlet pressure of the exhaust gas under standard conditions. 运行 This refers to the inlet or outlet pressure of the exhaust gas during online operation.

[0045] In some embodiments, the m w运行 To obtain it, follow these steps:

[0046] Based on the engine's operating speed and load under each standard condition, and the corresponding m 标准 The speed and load under standard conditions are obtained in m 标准 The correspondence between them;

[0047] The operating speed and load of the engine in online operation are interpolated into the corresponding relationship to obtain m. w运行 .

[0048] A second aspect of this application provides a computer device including a memory and a processor, the memory storing a computer program, characterized in that the processor executes the computer program to implement the steps of the online EGR flow detection method for an engine described in the first aspect.

[0049] A third aspect of this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the online EGR flow detection method for an engine as described in the first aspect.

[0050] A fourth aspect of this application provides an online EGR flow detection device for an engine, comprising:

[0051] The status parameter acquisition module is used to acquire the engine's operating speed and load during online operation.

[0052] The online testing module is used to test the online operating parameters of the engine, including the cooling medium inlet temperature T of the EGR cooler. 1运行 Cooling medium outlet temperature T 2运行 Exhaust gas inlet temperature T 3运行 Exhaust gas outlet temperature T 4运行 and exhaust gas pressure P 运行 ;

[0053] A memory, wherein the memory stores a computer program; and

[0054] A processor, which, when executing the computer program, implements the steps of the online EGR flow detection method for the engine described in the first aspect.

[0055] In some embodiments, the online testing module includes:

[0056] Temperature detection component, used to test the T 1运行 The T 2运行 The T 3运行 and the T 4运行 ;

[0057] Pressure detector, used to test the P 运行 .

[0058] In some embodiments, the online EGR flow detection device for the engine further includes:

[0059] The simulation testing module is used to test the simulated operating parameters of the engine under various standard conditions. These simulated operating parameters include the inlet temperature T of the cooling medium in the EGR cooler. 1标准 Cooling medium outlet temperature T 2标准 Exhaust gas inlet temperature T 3标准 Exhaust gas outlet temperature T 4标准 Standard flow rate of cooling medium (m³) w标准 EGR standard flow rate (m) e标准 and exhaust gas pressure P 标准 ;

[0060] The simulated operating parameters and standard state parameters under each standard state are stored in the memory. The standard state parameters include the engine's operating speed and load under the corresponding standard state. Attached Figure Description

[0061] Figure 1 This is a diagram illustrating the application environment of the online EGR flow detection method for an engine under standard engine conditions in one embodiment.

[0062] Figure 2 for Figure 1 The application environment diagram of the online EGR flow detection method in the online operation state of the engine;

[0063] Figure 3 This diagram illustrates the application environment of traditional EGR flow detection methods.

[0064] Explanation of reference numerals in the attached figures:

[0065] 101-EGR cooler, 102-Temperature detection component, 102a-Cooling medium inlet temperature sensor, 102b-Cooling medium outlet temperature sensor, 102c-Exhaust gas inlet temperature sensor, 102d-Exhaust gas outlet temperature sensor, 103-Pressure detector, 104-Liquid flow detector, 105-Gas flow detector, 106-Engine cylinder, 107-EGR valve, 108-Exhaust pipe, 109-Intake pipe, 110-Turbocharger, 111-Intake air cooler, 112-Throttle valve, 113-EGR cooling medium pipeline, 114-EGR exhaust gas pipeline.

[0066] 201-EGR cooler, 202-Temperature detector, 203-Venturi tube, 2031-First pressure detector, 2032-Second pressure detector, 204-Engine cylinder, 205-EGR valve, 206-Exhaust pipe, 207-Intake pipe, 208-Turbocharger, 209-Intake cooler, 210-Throttle valve, 211-EGR cooling medium pipeline, 212-EGR exhaust gas pipeline. Detailed Implementation

[0067] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of this application.

[0068] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0069] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0070] In this document, when an element is referred to as "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0071] The weights of the relevant components mentioned in the embodiments of this application can refer not only to the specific content of each component, but also to the proportional relationship between the weights of the components. Therefore, any scaling up or down of the content of the relevant components according to the embodiments of this application is within the scope disclosed in the embodiments of this application. Specifically, the weights mentioned in the embodiments of this application can be well-known units of mass in the chemical industry, such as μg, mg, g, and kg.

[0072] The online EGR flow detection method for engines provided in this application embodiment can be applied to, for example... Figure 1 and Figure 2 In the application environment shown, where Figure 1 This is a diagram illustrating the application environment under standard engine conditions. Figure 2 This is a diagram illustrating the application environment of the engine in online operation.

[0073] like Figure 1 As shown, the engine system includes an EGR system and other structures. Exhaust gas from engine cylinder 106 is discharged through exhaust pipe 108. Part of the exhaust gas enters the EGR system through EGR exhaust gas line 114, and the other part flows into turbocharger 110. The recirculated exhaust gas (i.e., EGR exhaust gas) entering the EGR system is cooled by EGR cooler 101, then enters intake pipe 109 through EGR valve 107 and mixes with fresh gas therein, before flowing into engine cylinder 106. The EGR system also includes a temperature detection component 102, a pressure detector 103, a liquid flow detector 104, a gas flow detector 105, and an EGR cooling medium line 113 for transmitting the cooling medium. The temperature detection component 102 includes a cooling medium inlet temperature sensor 102a and a cooling medium outlet temperature sensor 102b installed on the EGR cooling medium line 113, and an exhaust gas inlet temperature sensor 102c and an exhaust gas outlet temperature sensor 102d installed on the EGR exhaust gas line 114. Cooling medium inlet temperature sensor 102a is used to measure the cooling medium inlet temperature T. 1标准 The cooling medium outlet temperature sensor 102b is used to measure the cooling medium outlet temperature T. 2标准 The exhaust gas inlet temperature sensor 102c is used to measure the exhaust gas inlet temperature T. 3标准The exhaust gas temperature sensor 102d is used to measure the exhaust gas outlet temperature T. 4标准 Pressure detector 103 is used to measure EGR pressure P 标准 The liquid flow detector 104 is used to measure the flow rate of the cooling medium (m). w标准 The gas flow detector 105 is used to measure the EGR flow rate (m). e标准 The engine system also includes an intake air cooler 111 and a throttle valve 112, which are used to regulate the temperature and flow rate of fresh air, respectively.

[0074] like Figure 2 As shown, in the online operating state of the engine, the engine system does not contain the liquid flow detector 104 and the gas flow detector 105; the other structures of the engine system are similar to those in the standard state. In the online operating state, the coolant inlet temperature sensor 102a is used to measure the coolant inlet temperature T. 1运行 The cooling medium outlet temperature sensor 102b is used to measure the cooling medium outlet temperature T. 2运行 The exhaust gas inlet temperature sensor 102c is used to measure the exhaust gas inlet temperature T. 3运行 The exhaust gas outlet temperature sensor 102d is used to measure the exhaust gas outlet temperature T. 4运行 Pressure detector 103 is used to measure EGR pressure P 运行 In addition, the cooling medium flow rate (m) w运行 It can be controlled by speed and load with m 标准 The correspondence between them is obtained. It should be noted that the standard state and online operating state of the engine can be measured using the same testing equipment at the same location in the engine system, for example, the same coolant inlet temperature sensor 102a can be used to test T. 1标准 and T 1运行 Different testing equipment can also be used for measurement, and this application does not limit this.

[0075] Depend on Figure 2 As can be seen, the engine system in online operation does not have a gas flow detector 105 installed, so the flow resistance encountered by the recirculated exhaust gas is almost negligible. However, traditional EGR flow detection methods mostly involve connecting a venturi tube to the exhaust gas line to test the exhaust gas flow rate. This increases the flow resistance in the line, affecting the transmission of the recirculated exhaust gas. For example, the application environment of the traditional EGR flow detection method is as follows... Figure 3As shown, after being cooled by the EGR cooler 201, the recirculated exhaust gas needs to pass through the Venturi tube 203 to test its flow rate before entering the EGR valve 205 and the intake pipe 207. The Venturi tube 203 determines the exhaust gas flow rate based on the pressure at the inlet section measured by the first pressure detector 2031 and the pressure at the throat section measured by the second pressure detector 2032. A smaller throat section area results in more accurate test results, but also increases the flow resistance to the exhaust gas. Therefore, traditional technology presents a trade-off between measurement accuracy and pipeline flow resistance when measuring EGR flow rate during engine operation. Figure 3 The other structures are all existing structures and will not be described in detail here.

[0076] The online EGR flow detection method for engines provided in the embodiments of this application will be described in detail below.

[0077] The online EGR flow detection method for an engine provided in this application includes the following steps S100 to S400.

[0078] S100: Simulate engine operation under N standard conditions and obtain the simulated operating parameters of the engine under each standard condition. The simulated operating parameters include the inlet temperature T of the cooling medium of the EGR cooler. 1标准 Cooling medium outlet temperature T 2标准 Exhaust gas inlet temperature T 3标准 Exhaust gas outlet temperature T 4标准 Cooling medium flow rate (m) w标准 EGR flow rate m e标准 and EGR pressure P 标准 N is an integer ≥2, and at least one of the engine's operating speed and load is different under each standard condition.

[0079] The standard state is a simulated operating state preset based on the engine's actual operating speed and load range. By changing the operating speed or load, N different standard states can be obtained. The load refers to the load factor, specifically the ratio of the engine's output power at a preset torque to the maximum torque that can be output at that preset torque. It should be noted that there is a one-to-one correspondence between the standard states and the simulated operating parameters, and the number of standard states is the same as the number of simulated operating parameters. Furthermore, the cooling medium can be cooling water or other refrigerants.

[0080] S200. Based on the simulated operating parameters of the engine under various standard conditions, obtain the heat absorption power W of the cooling medium under each standard condition. w标准 and exhaust gas heat dissipation power W e标准 According to the heat absorption power W of each cooling medium w标准 and the heat dissipation power of each exhaust gas W e标准 To obtain W under each standard statew标准 With W e标准 The correction factor δ between 标 allow.

[0081] Understandably, the exhaust gas from the engine cylinders is relatively hot and needs to be cooled before returning to the cylinders. The exhaust gas flows into the EGR cooler and exchanges heat with the cooling medium, thus achieving cooling. The heat absorption power W of the cooling medium can be obtained from the simulated operating parameters acquired in step S100. w标准 and exhaust gas heat dissipation power W e标准 Exhaust gas heat dissipation power W e标准 Besides being absorbed by the cooling medium, a small portion is also lost through thermal radiation, therefore W w标准 and W e标准 Not exactly equal, according to W w标准 and W e标准 The relationship between them can be corrected by the coefficient δ. 标准 It should be noted that the standard state and δ 标准 It is also a one-to-one correspondence, with the number of standard states and the correction factor δ 标准 The quantities are the same.

[0082] S300: Obtain the engine's operating speed and load, as well as online operating parameters, under online operating conditions. These online operating parameters include the EGR cooler's cooling medium inlet temperature T. 1运行 Cooling medium outlet temperature T 2运行 Exhaust gas inlet temperature T 3运行 Exhaust gas outlet temperature T 4运行 Cooling medium flow rate (m) w运行 and EGR pressure P 运行 .

[0083] Online operating status refers to the actual operating state of the engine. Understandably, to improve the accuracy of the test results, the online operating status must use the same cooling medium as the standard status in step S100, and the online operating parameters must also be obtained using the same method as the standard status in step S100. It should be noted that m w运行 The operating speed and load under standard conditions can be determined based on the engine's simulated operating parameters, online operating speed and load, and online operating parameters. For example, this can be determined by looking up the operating speed and load under standard conditions and the cooling medium flow rate (m). w标准 The relationship table, combined with the specific operating speed and load during online operation, yields m. w运行 m w运行 It can also be measured using liquid flow reagents.

[0084] S400: Based on the correction coefficients under each standard condition, the operating speed and load of the engine under online operating conditions, and the online operating parameters, the EGR flow rate of the engine under online operating conditions is obtained.

[0085] Understandably, the standard state is determined based on the engine's operating speed and load, and there is a one-to-one correspondence between the standard state and the correction factor. Therefore, the correction factor in the online operating state can be determined by combining the engine's operating speed and load in the online operating state with the operating speed and load in the standard state, and the EGR flow rate in the online operating state can be obtained further.

[0086] The above-described online EGR flow detection method simulates engine operation under N standard conditions and calculates the flow rate based on the T values ​​obtained under each standard condition. 1标准 T 2标准 T 3标准 T 4标准 m w标准 m e标准 and P 标准 Determine W under the corresponding standard state. w标准 With W e标准 Correction coefficients between them; then obtain the engine speed, load, and T under online operating conditions. 1运行 T 2运行 T 3运行 T 4运行 and P 运行 Based on the above data under online operation conditions and combined with correction factors, the EGR flow m under this operation condition is determined. e运行 The above testing method eliminates the need for EGR flow testing using a venturi tube during engine operation, thus avoiding any increase in flow resistance in the EGR pipeline. Furthermore, the correction factor δ... 标准 It represents W w标准 With W e标准 The relationship between W and the engine under different speeds and loads. e标准 The difference is related to the flow rate of the exhaust gas, so it can be corrected using a correction factor δ. 标准 To establish the relationship between exhaust gas flow rate and engine speed and load, and then based on the δ value of the online operating status... 运行 To more accurately determine the EGR flow rate in the online operating state, and to improve the accuracy of the detection results by simulating the engine's operating state using N standard states.

[0087] In some embodiments, the operating speed and load for N standard states are determined according to the following steps:

[0088] S101. Select a different standard operating speeds;

[0089] S102. Set b different standard loads at each operating speed;

[0090] S103. Using a standard operating speed and a standard load as a set of standard state parameters, the simulated operation of the engine under standard conditions means that the engine is operated under standard state parameters.

[0091] Where N = a × b, and a and b are each independently selected from integers ≥ 1.

[0092] Understandably, we first determine 'a' standard operating speeds, and then set 'b' loads at each standard operating speed to obtain N standard states. It should be noted that although 'a' and 'b' are each independently selected from integers ≥ 1, N must still be an integer ≥ 2, meaning that 'a' and 'b' cannot both be 1.

[0093] In some embodiments, the magnitudes of the *a* different operating speeds are distributed in an equally spaced gradient. Specifically, the *a* different operating speeds are arranged from largest to smallest or smallest to largest, with the difference between any two adjacent speeds being equal. Furthermore, the range of the *a* different operating speeds is from engine idle speed to rated speed.

[0094] In some embodiments, a is an integer ≥ 4.

[0095] In the above embodiments, by setting equally spaced gradient distributions of operating speeds or adjusting the value of 'a', a suitable number of standard states can be obtained, thereby improving the accuracy of the detection results.

[0096] In some embodiments, the magnitudes of the b different loads are distributed in an equally spaced gradient. Specifically, the b different loads are arranged from largest to smallest or smallest to largest, with the difference between any two adjacent loads being equal. Further, the values ​​of the b different loads range from 0 to 100%.

[0097] In some of these embodiments, b is an integer ≥ 4.

[0098] In the above embodiments, by setting an equally spaced gradient distribution of load or adjusting the value of b, a suitable number of standard states can be obtained, thereby improving the accuracy of the detection results.

[0099] In some embodiments, S200 includes the following steps:

[0100] S201, according to T 1标准 T 2标准 m w标准 The W value under the corresponding standard state is obtained from formula (1). w标 allow;

[0101] S202, according to T 3标准T 4标准 m m标准 The W value under the corresponding standard state is obtained from formula (2). e标 allow;

[0102] S203, Calculate δ according to formula (3) 标准 ;

[0103] Formulas (1) to (3) are as follows:

[0104] W w =C w ×m w ×(T2-T1) Formula (1),

[0105] W e =C e ×m e ×(T3-T4) Formula (2),

[0106] δ=W e / W w Formula (3),

[0107] In formulas (1) to (3), T1 is the inlet temperature of the cooling medium, T2 is the outlet temperature of the cooling medium, T3 is the inlet temperature of the exhaust gas, T4 is the outlet temperature of the exhaust gas, and C w For the specific heat capacity of the cooling medium, m w C represents the flow rate of the cooling medium. e For the specific heat capacity of the exhaust gas, m e This refers to the exhaust gas flow rate.

[0108] Understandably, C w The temperature variation is small within the engine's operating temperature range, so its value can be considered a constant. Furthermore, the correction coefficient δ corresponding to each standard state can be obtained using formulas (1) to (3) and the simulated operating parameters. 标准 Furthermore, due to the flow rate m w and m e It refers to the mass of fluid passing through the cross section of the pipe per unit time. Therefore, the heat absorbed or dissipated per unit time is calculated by formula (1) and formula (2), which is the heat absorption power or heat dissipation power. In this paper, W is used to represent heat power instead of P to distinguish it from P which represents pressure.

[0109] In some embodiments, the specific heat capacity C of the exhaust gas under various standard conditions is... e标准 Determine using the following steps:

[0110] According to T 3标准 or T 4标准 and P 标准 Determine the components of the exhaust gas and the molar content of each component under the corresponding standard conditions;

[0111] According to formula (4), C is obtained. e标准 ;

[0112] Formula (4) is as follows:

[0113] C e = a1×C1+……+a n-1 ×C n-1 +a n ×C n Formula (4),

[0114] a1 and C1 are the molar content and specific heat capacity of the first component in the exhaust gas, respectively. n-1 and C n-1 These represent the molar content and specific heat capacity of the (n-1)th component in the exhaust gas, respectively, a n and C n These represent the molar content and specific heat capacity of the nth component in the exhaust gas, respectively.

[0115] Specifically, the composition and content of the exhaust gas are related to its temperature and pressure. Those skilled in the art can determine the components of the exhaust gas under standard conditions and the molar content of each component by referring to the table showing the relationship between exhaust gas composition and temperature and pressure, and confirm C according to formula (4). e标准 It should be noted that if T is used in this step... 3标准 and P 标准 Once the components of the exhaust gas and the molar content of each component are determined under standard conditions, T will be used in subsequent step S400. 3运行 and P 运行 Determine the components of the exhaust gas under standard conditions and the molar content of each component. Similarly, if this step uses T... 4标准 and P 标准 Then, in step S400, T is used. 4运行 and P 运行 .

[0116] In some embodiments, S400 includes the following steps:

[0117] S401. Based on the engine's operating speed and load under each standard condition and the corresponding correction factor δ 标准 The speed and load under standard conditions and the correction factor δ are obtained. 标准 The relationship between them;

[0118] S402. Interpolate the engine's operating speed and load under online operating conditions into the correction relationship to obtain the corresponding correction coefficient δ. 运行 ;

[0119] S403, according to T 1运行 T 2运行Using formula (1), the heat absorption power W of the cooling medium under online operating conditions is obtained. w运行 ;

[0120] S404, according to δ 运行 W w运行 Using formula (3), the exhaust gas heat dissipation power W under online operation is obtained. e运行 ;

[0121] S405, according to T 3运行 or T 4运行 and P 运行 The components and molar content of the exhaust gas under online operation conditions are determined, and C is obtained according to formula (4). e运行 ;

[0122] S406, according to W e运行 C e运行 T 3运行 T 4运行 Using formula (2), the EGR flow rate m in the operating state is obtained. e运行 .

[0123] Interpolation refers to adding a continuous function to discrete data so that the continuous curve passes through all given discrete data points. Interpolation is an important method for approximating discrete functions, allowing us to estimate the approximate value of a function at other points based on its values ​​at a finite number of points. Specifically, in this embodiment, the rotational speed and load, along with the corresponding correction coefficient δ, are first established under various standard conditions. 标准 The relationship can be presented in tabular form or other formats; subsequently, by interpolating the speed and load under online operating conditions into the above correction relationship, the correction coefficient δ corresponding to this online operating condition can be obtained. 运行 .

[0124] Furthermore, in this embodiment, the engine's operating speed, load, and online operating parameters are obtained using step S300, and the EGR flow rate m in the operating state can be calculated using formulas (1) to (4). e运行 This allows for EGR flow rates that can be obtained without using a venturi tube, and with almost no increase in EGR pipeline flow resistance.

[0125] In some of these embodiments, P 标准 P is the inlet or outlet pressure of the exhaust gas under standard conditions. 运行 This refers to the inlet or outlet pressure of the exhaust gas during online operation.

[0126] Understandably, the heat exchange process of exhaust gas in an EGR cooler is an isobaric process. Therefore, the inlet pressure and outlet pressure of the exhaust gas in the EGR cooler are almost equal. Thus, either the inlet pressure or the outlet pressure of the exhaust gas under standard conditions can be used as P. 标准 Similarly, P 运行 Alternatively, either the inlet pressure or the outlet pressure of the exhaust gas during online operation can be used.

[0127] In some embodiments, m w运行 Obtain it by following these steps:

[0128] Based on the engine's operating speed and load under various standard conditions and the corresponding m 标准 The speed and load under standard conditions are obtained in m 标准 The correspondence between them;

[0129] The engine's operating speed and load under online operation are interpolated into the corresponding relationship to obtain m. w运 OK.

[0130] Specifically, in this embodiment, the rotational speed and load, and their corresponding m, are first established under each standard condition. 标准 The correspondence can be presented in tabular form or other forms; subsequently, by interpolating the speed and load in the online operating state into the above correspondence, the corresponding m for this online operating state can be obtained. w运行 It should be noted that this embodiment does not require a liquid flow meter to be installed on the EGR cooler to obtain the flow rate (m). w运行 Therefore, it hardly affects the transmission of the cooling medium, but in other implementations, the flow rate of the cooling medium can also be obtained by setting a liquid flow meter.

[0131] This application also provides a computer device, including a memory and a processor. The memory stores a computer program, and when the processor executes the computer program, it implements the steps of the above-described online EGR flow detection method for an engine.

[0132] In some embodiments, the computer device may be a terminal. The computer device includes a processor, memory, network interface, display screen, and input device connected via a system bus. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The network interface of the computer device is used to communicate with external terminals via a network connection. When the computer program is executed by the processor, it implements any of the inkjet printing methods described above. The display screen of the computer device may be a liquid crystal display (LCD) or an electronic ink display. The input device may be a touch layer covering the display screen, buttons, a trackball, or a touchpad mounted on the computer device casing, or an external keyboard, touchpad, or mouse, etc.

[0133] This application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described online EGR flow detection method for an engine.

[0134] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided by this invention can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM), etc.

[0135] This application also provides an online EGR flow detection device for an engine, comprising:

[0136] The status parameter acquisition module is used to acquire the engine's operating speed and load during online operation.

[0137] The online testing module is used to test the engine's online operating parameters, including the EGR cooler's cooling medium inlet temperature T. 1运行 Cooling medium outlet temperature T 2运行 Exhaust gas inlet temperature T 3运行 Exhaust gas outlet temperature T 4运行 and exhaust gas pressure P 运行 ;

[0138] Memory, which stores computer programs; and

[0139] The processor, when executing the computer program, implements the steps of the above-described online EGR flow detection method for the engine.

[0140] Understandably, the aforementioned memory stores the rotational speed, load, simulated operating parameters, and corresponding correction coefficients δ for each standard state. 标准 The status parameter acquisition module can obtain the speed and load of the online operating status, the online detection module can measure the online operating parameters, and the processor can obtain the EGR flow of the engine in the online operating status by executing the computer program.

[0141] In some embodiments, the online testing module includes:

[0142] Temperature sensing component, used to test T 1运行 T 2运行 T 3运行 and T 4运行 ;

[0143] Pressure detector, used to test P 运行 .

[0144] Specifically, the temperature detection component includes four temperature detectors, each testing T. 1运行 T 2运行 T 3运行 and T 4运行 The temperature detector can be a temperature sensor, and the pressure detector can be a pressure sensor. Understandably, the online EGR flow monitoring device also includes an EGR cooling medium pipeline for conveying the cooling medium, and an EGR exhaust gas pipeline for conveying the exhaust gas. The temperature detector and pressure detector are respectively installed at corresponding positions in the EGR cooling medium pipeline or the EGR exhaust gas pipeline to test T... 1运行 T 2运行 T 3运行 T 4运行 and P 运行 .

[0145] In some embodiments, the online EGR flow detection device for the engine further includes:

[0146] The simulation testing module is used to test the simulated operating parameters of the engine under various standard conditions. These simulated operating parameters include the EGR cooler's cooling medium inlet temperature T. 1标准 Cooling medium outlet temperature T 2标准 Exhaust gas inlet temperature T 3标准 Exhaust gas outlet temperature T 4标准 Standard flow rate of cooling medium (m³) w标准 EGR standard flow rate (m) e标准 and exhaust gas pressure P 标准 ;

[0147] The simulated operating parameters and standard state parameters under each standard state are stored in the memory. The standard state parameters include the engine's operating speed and load under the corresponding standard state.

[0148] Understandably, during the calibration phase before the engine leaves the factory, the simulation testing module also obtains the speed, load, simulated operating parameters, and corresponding correction coefficients δ corresponding to each standard state. 标准 And store it in memory.

[0149] In some embodiments, the simulation detection module includes:

[0150] Temperature sensing component, used to test T 1标准 T 2标准 T 3标准 and T 4标准 ;

[0151] Pressure detector, used to test P 标准 ;

[0152] Liquid flow detector, used to obtain the standard flow rate (m) of cooling medium. w标准 ;and

[0153] Gas flow detector, used to obtain EGR standard flow rate (m). e标准 .

[0154] For example, the temperature detection component in the simulation detection module can use the same set of temperature detection components as the online testing module, and the pressure detector in the simulation detection module can use the same pressure detector as the online testing module. In other words, in the above example, the difference between the simulation detection module and the online testing module is that the simulation detection module includes two flow detectors; removing these two flow detectors yields the online testing module.

[0155] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0156] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for online detection of EGR flow in an engine, characterized in that, Includes the following steps: S100. Simulate engine operation under N standard conditions and obtain simulated operating parameters of the engine under each standard condition. These simulated operating parameters include the inlet temperature T of the cooling medium in the EGR cooler. 1标准 Cooling medium outlet temperature T 2标准 Exhaust gas inlet temperature T 3标准 Exhaust gas outlet temperature T 4标准 Cooling medium flow rate (m) w标准 EGR flow rate m e标准 and EGR pressure P 标准 N is an integer ≥2, and at least one of the engine's operating speed and load is different under each standard condition; S200. Based on the simulated operating parameters of the engine under each standard condition, obtain the cooling medium heat absorption power W under each standard condition. w标准 and exhaust gas heat dissipation power W e标准 According to the heat absorption power W of each cooling medium w标准 and the heat dissipation power of each exhaust gas W e标准 To obtain W under each standard state w标准 With the W e标准 The correction factor δ between 标准 ; S300: Obtain the engine's operating speed and load, as well as online operating parameters, under online operating conditions. These online operating parameters include the EGR cooler's cooling medium inlet temperature T. 1运行 Cooling medium outlet temperature T 2运行 Exhaust gas inlet temperature T 3运行 Exhaust gas outlet temperature T 4运行 Cooling medium flow rate (m) w运行 and EGR pressure P 运行 ; S400. Based on the correction coefficients under each standard condition, the operating speed and load of the engine under online operating conditions, and the online operating parameters, the EGR flow rate of the engine under online operating conditions is obtained.

2. The online EGR flow detection method for an engine as described in claim 1, characterized in that, The operating speed and load for the N standard states are determined according to the following steps: Select a different standard operating speeds; b different standard loads are set at each operating speed; Using a standard operating speed and a standard load as a set of standard state parameters, simulating the engine's operation under standard conditions means operating the engine under the standard state parameters. Where N = a × b, and a and b are each independently selected from integers ≥ 1.

3. The online EGR flow detection method for an engine as described in claim 2, characterized in that, The detection method satisfies at least one of the following (1) to (4): (1) The magnitudes of the a different operating speeds are distributed in an equally spaced gradient; (2) a is an integer ≥ 4; (3) The magnitudes of the b different loads are distributed in an equally spaced gradient; (4) b is an integer greater than or equal to 4.

4. The online EGR flow detection method for an engine as described in any one of claims 1 to 3, characterized in that, S200 includes the following steps: According to the T 1标准 The T 2标准 The m w标准 The W under the corresponding standard state is obtained by combining formula (1). w标准 ; According to the T 3标准 The T 4标准 The m w标准 And formula (2) yields the W under the corresponding standard state. e标准 ; Calculate the δ according to formula (3) 标准 ; Formulas (1) to (3) are as follows: W w =C w ×m w ×(T2-T1) formula (1), W e =C e ×m e ×(T3-T4) Formula (2), δ=W e / W w Formula (3), In formulas (1) to (3), T1 is the inlet temperature of the cooling medium, T2 is the outlet temperature of the cooling medium, T3 is the inlet temperature of the exhaust gas, T4 is the outlet temperature of the exhaust gas, and C w For the specific heat capacity of the cooling medium, m w C represents the flow rate of the cooling medium. e For the specific heat capacity of the exhaust gas, m e This refers to the exhaust gas flow rate.

5. The online EGR flow detection method for an engine as described in claim 4, characterized in that, Specific heat capacity C of exhaust gas under various standard conditions e标准 Determine using the following steps: According to the T 3标准 or T 4标准 and the P 标准 Determine the components of the exhaust gas and the molar content of each component under the corresponding standard conditions; According to formula (4), C is obtained. e标准 ; Formula (4) is as follows: C e =a1×C1+……+a n-1 ×C n-1 +a n ×C n Formula (4), a1 and C1 are the molar content and specific heat capacity of the first component in the exhaust gas, respectively. n-1 and C n-1 These represent the molar content and specific heat capacity of the (n-1)th component in the exhaust gas, respectively, a n and C n These represent the molar content and specific heat capacity of the nth component in the exhaust gas, respectively.

6. The online EGR flow detection method for an engine as described in claim 5, characterized in that, S400 includes the following steps: Based on the engine's operating speed and load under each standard condition, and the corresponding correction factor δ 标准 The speed and load under standard conditions and the correction factor δ are obtained. 标准 The relationship between them; The engine's operating speed and load during online operation are interpolated into the correction relationship to obtain the corresponding correction coefficient δ. 运行 ; According to the T 1运行 The T 2运行 Using the formula (1), the heat absorption power W of the cooling medium under online operation is obtained. w运行 ; According to the δ 运行 The W w运行 Using the formula (3), the exhaust gas heat dissipation power W under online operation is obtained. e运行 ; According to the T 3运行 or the T mentioned 4运行 and the P 运行 The components and molar content of the exhaust gas under online operation conditions are determined, and C is obtained according to formula (4). e运行 ; According to the W e运行 The C e运行 The T 3运行 The T 4运行 Using the formula (2), the EGR flow rate m of the operating state is obtained. e运行 .

7. The online EGR flow detection method for an engine as described in any one of claims 1 to 3, characterized in that, The P 标准 P is the inlet or outlet pressure of the exhaust gas under standard conditions. 运行 This refers to the inlet or outlet pressure of the exhaust gas during online operation.

8. The online EGR flow detection method for an engine as described in any one of claims 1 to 3, characterized in that, The m w运行 To obtain it, follow these steps: Based on the engine's operating speed and load under each standard condition, and the corresponding m 标准 The speed and load under standard conditions are obtained in m 标准 The correspondence between them; The operating speed and load of the engine in online operation are interpolated into the corresponding relationship to obtain m. w运行 .

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the online EGR flow detection method for the engine according to any one of claims 1 to 8.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the online EGR flow detection method for the engine according to any one of claims 1 to 8.

11. An online EGR flow detection device for an engine, characterized in that, The online EGR flow monitoring device for the engine includes: The status parameter acquisition module is used to acquire the engine's operating speed and load during online operation. The online testing module is used to test the online operating parameters of the engine, including the cooling medium inlet temperature T of the EGR cooler. 1运行 Cooling medium outlet temperature T 2运行 Exhaust gas inlet temperature T 3运行 Exhaust gas outlet temperature T 4运行 and exhaust gas pressure P 运行 ; A memory, wherein the memory stores a computer program; and A processor, which, when executing the computer program, implements the steps of the online EGR flow detection method for the engine according to any one of claims 1 to 8.

12. The online EGR flow detection device for an engine as described in claim 11, characterized in that, The online detection module includes: Temperature detection component, used to test the T 1运行 The T 2运行 The T 3运行 and the T 4运行 ; Pressure detector, used to test the P 运行 .

13. The online EGR flow detection device for an engine as described in claim 11 or 12, characterized in that, The online EGR flow monitoring device for the engine also includes: The simulation testing module is used to test the simulated operating parameters of the engine under various standard conditions. These simulated operating parameters include the inlet temperature T of the cooling medium in the EGR cooler. 1标准 Cooling medium outlet temperature T 2标准 Exhaust gas inlet temperature T 3标准 Exhaust gas outlet temperature T 4标准 Standard flow rate of cooling medium (m³) w标准 EGR standard flow rate (m) e标准 and exhaust gas pressure P 标准 ; The simulated operating parameters and standard state parameters under each standard state are stored in the memory. The standard state parameters include the engine's operating speed and load under the corresponding standard state.

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