A method for matching the performance of a diesel engine injector
By calculating the injector structural parameters and automatically processing calibration data, the problem of low matching efficiency between injectors and engines was solved, achieving full operating condition coverage and system synergy, reducing development costs and improving efficiency.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- KUNMING YUNNEI POWER
- Filing Date
- 2026-05-09
- Publication Date
- 2026-07-21
AI Technical Summary
Existing methods for matching fuel injectors with engines rely on engineers' experience, resulting in long development cycles, high costs, and difficulty in covering all operating conditions and evaluating system compatibility.
By calculating the injector structural parameters, selecting the automatic calibration operating point, and processing the data, the optimal combination of injector flow rate, number of orifices, and nozzle cone angle is selected. Combined with the LCCE development goals, automatic calibration data processing is performed to achieve precise matching between the injector and the engine.
It improves the matching efficiency between fuel injectors and diesel engines, achieves full operating condition coverage, reduces development costs, improves development efficiency, and ensures system synergy.
Smart Images
Figure CN122432683A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of automotive engine testing technology, and in particular to a method for matching the performance of diesel engine injectors. Background Technology
[0002] The fuel injector is a core actuator in the internal combustion engine's fuel system. Its core function is to inject precisely metered fuel in a highly atomized form into the engine's intake manifold or cylinders at the correct time, according to the instructions of the engine control unit (ECU). It is a key component for improving engine power, fuel economy, emissions performance, and NVH (noise, vibration, and harshness). Its performance parameters, such as dynamic flow range, response time, minimum controllable fuel quantity, atomization characteristics, durability, and reliability, must be precisely matched with the engine's operating conditions, such as engine speed and load. Improper matching can lead to problems such as insufficient engine power, increased fuel consumption, increased emissions, and increased noise and vibration. Therefore, precise matching between the fuel injector and the engine is a crucial aspect of fuel injector development.
[0003] Currently, fuel injector selection mainly relies on engineers' experience, involving repeated testing on engine benches. This process is not only time-consuming and labor-intensive, but also costly and inefficient. Furthermore, traditional methods often focus on a few operating conditions such as rated speed, maximum torque, and partial load, failing to cover the performance matching requirements of the engine under all operating conditions (such as high speed, low speed, and transient conditions). Additionally, fuel injectors are coupled with the engine's intake and fuel injection systems, making it difficult for traditional matching methods to comprehensively evaluate injector performance and neglecting the overall system synergy.
[0004] The shortcomings of existing technologies in terms of injector-engine matching efficiency, full-condition coverage, and system synergy have spurred the development of more efficient and precise injector performance matching methods. Summary of the Invention
[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for matching the performance of diesel engine injectors.
[0006] The objective of this invention is achieved through the following technical solution: a method for matching the performance of a diesel engine injector, comprising the following steps:
[0007] S101: Selection of injector structural parameters. These parameters include selection of injection air flow rate, number of injector orifices, and injector orifice cone angle.
[0008] In selecting the fuel injection air flow rate, the formula for calculating the fuel injection air volume is: , This refers to the injector flow rate, expressed in L / min. The nozzle flow rate coefficient is... This represents the total cross-sectional area of the nozzle flow, in cm².2 , This represents the pressure difference before and after the nozzle, expressed in MPa. Fuel density, in kg / m³ 3 For injectors with the same number of holes, cone angle, but different flow rates, select the best cone height based on the first set of injectors, and then select other injectors with different flow rates based on the best cone height.
[0009] In selecting the number of injector holes, the formula for calculating the number of injector holes is as follows: ,in, This refers to the number of fuel injection holes. Eddy ratio, The injection duration angle is expressed in units of 1. For injectors with the same cone angle and flow rate but different numbers of holes, select the best cone height based on the first injector, and then select other injectors with different numbers of holes based on the best cone height.
[0010] In the selection of injector nozzle cone angle, for injectors with the same flow rate and number of nozzles, different nozzle cone angles are selected. The optimal convex height is selected based on the first injector, and then other injectors with different nozzle cone angles are selected based on the optimal convex height. The nozzle cone angle is 140~160°.
[0011] S102: Determination of the optimal structural parameters for the fuel injector design.
[0012] S103: Selecting automatic calibration operating points based on the optimal solution.
[0013] S104: Process the automatic calibration data according to the LCCE development goals.
[0014] S105: Compare and select the best option to determine the final solution.
[0015] Optionally, in step S102, based on the same external characteristics and maximum explosion pressure, the total power characteristics, load characteristics and propulsion characteristics of the diesel engine are tested, and the parameters of the injector are tested at the same time to confirm whether the injector capability meets the requirements. From the test data set, the optimal structural parameters of the injector scheme that meet the current configuration are selected, namely the best combination of injector flow rate, number of orifices and nozzle cone angle.
[0016] Optionally, step S103 includes selecting emission area points and non-emission area points. When selecting emission area points, the grid is divided and WHTC is clustered according to the definition of the WNTE cycle control area. When selecting non-emission area points, the low-speed full-load condition is selected as the feature point. The low-speed speed of the 4-cylinder engine is set to 1000 r / min, and the low-speed speed of the 6-cylinder engine is set to 800 r / min.
[0017] Optionally, when performing clustering, WHTC selects three small torque points. For different models, the load rate of these three points can be increased accordingly to make the test and data stable and reliable, and to facilitate the evaluation of the effect of the post-vortex temperature on the catalytic efficiency.
[0018] Optionally, during processing, step S104 ,in, This is the specific fuel consumption under this operating condition, expressed in g / kWh. This refers to the original engine emissions under this operating condition, expressed in g / kWh. This represents the target specific emissions under this operating condition, expressed in g / kWh. The price of Tilan is in yuan / L. The price of diesel fuel is expressed in yuan / L. The automatic calibration test data is exported as a standard template. The original engine NOx ratio, average catalyst temperature, and space velocity are calculated. Then, interpolation is performed using the catalyst limiting efficiency MAP to obtain the actual automatic calibration catalyst limiting efficiency under various operating conditions. Finally, a 3% margin is reserved based on the interpolated limiting efficiency. A 5% limit was set, and the engineering efficiency MAP was simulated to prevent ammonia leakage. Based on the catalyst limit efficiency and original NOx emissions at each operating point, the target NOx emission was calculated, and the target specific NOx of the final aftertreatment was calculated. The test data of each operating point were plotted, and the optimal LCCE result was obtained under the constraint conditions that the final specific NOx, 415 smoke opacity, maximum explosion pressure and highest after-vortex temperature meet the constraints.
[0019] Optionally, in step S600, the data is automatically calibrated, and a graph is drawn for comparison with the final NOx emission ratio on the horizontal axis and LCCE, specific fuel consumption, 415 smoke opacity, explosion pressure, and in-vortex / out-of-vortex temperature on the vertical axis, and the optimal configuration scheme is selected.
[0020] The present invention has the following advantages: the diesel engine injector performance matching method of the present invention can improve the matching efficiency between injectors and diesel engines, achieve full operating condition coverage, ensure system synergy, and at the same time, facilitate rapid verification of injectors, advance the test process, reduce the development cost of injector performance matching, and improve development efficiency. Attached Figure Description
[0021] Figure 1 This is a flowchart of the process of the present invention.
[0022] Figure 2 Schematic diagram of injector replacement
[0023] In the diagram, 1-injector, 2-threaded bushing, 3-high-pressure connector. Detailed Implementation
[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0025] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.
[0026] It should be noted that, unless otherwise specified, the embodiments and features described in this invention can be combined with each other.
[0027] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0028] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. In addition, the terms "first," "second," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0029] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.
[0030] like Figure 1 As shown, a method for matching the performance of a diesel engine injector includes the following steps:
[0031] S101: Selection of Injector Structural Parameters. Based on the injector structural parameters and diesel engine performance parameters, calculate and screen injectors that initially meet the requirements of the diesel engine in terms of flow rate, number of orifices, and nozzle cone angle. Simultaneously, select the optimal crown height for the first batch of injectors, and then select other injectors with different flow rates, number of orifices, and nozzle cone angles based on this optimal crown height. Specifically, the injector structural parameters include the selection of injection air flow rate, the selection of the number of injector orifices, and the selection of the injector nozzle cone angle. In the selection of injection air flow rate, the formula for calculating the injection air flow rate is: , This refers to the injector flow rate, expressed in L / min. The nozzle flow rate coefficient is... This represents the total cross-sectional area of the nozzle flow, in cm². 2 , This represents the pressure difference before and after the nozzle, expressed in MPa. Fuel density, in kg / m³ 3 For injectors with the same number of holes, cone angle, but different flow rates, select the best cone height based on the first set of injectors, and then select other injectors with different flow rates based on the best cone height.
[0032] In selecting the number of injector holes, the formula for calculating the number of injector holes is as follows: ,in, This refers to the number of fuel injection holes. Eddy ratio, The injection duration angle is expressed in units of 1. For injectors with the same cone angle and flow rate but different numbers of holes, select the best cone height based on the first injector, and then select other injectors with different numbers of holes based on the best cone height.
[0033] In the selection of injector nozzle cone angle, for injectors with the same flow rate and number of nozzles, different nozzle cone angles are selected. The optimal convex height is selected based on the first injector, and then other injectors with different nozzle cone angles are selected based on the optimal convex height. The nozzle cone angle is 140~160°.
[0034] S102: Determination of the optimal structural parameters for the fuel injector design.
[0035] S103: Selecting automatic calibration operating points based on the optimal solution.
[0036] S104: Process the automatic calibration data according to the LCCE development goals.
[0037] S105: Compare and select the best option to determine the final solution.
[0038] In this embodiment, in step S102, based on the same external characteristic maximum explosion pressure, the total power characteristics, load characteristics, and propulsion characteristics of the diesel engine are tested. Simultaneously, the parameters of the injectors are tested to confirm whether the injector capacity meets the requirements. From the test data set, the optimal structural parameters of the injector scheme that meet the current configuration are selected, namely the best combination of injector flow rate, number of orifices, and nozzle cone angle. Figure 2 As shown, the replacement process for injector 1 requires a five-step procedure: 1. Insert injector 1 into the cylinder head, with a recommended clamping force of 1.2 kN; 2. Completely loosen the clamping block or flange to ensure injector 1 is correctly positioned within the cylinder head (clearance fit); 3.5~8 kN pre-tighten the high-pressure connector 3, equivalent to applying a torque of 15~20 Nm to the threaded bushing 2; 4. Press injector 1 firmly, applying the necessary clamping force, with a maximum of 15 kN; 5. Tighten the high-pressure connector 3 to ensure a sealing pressure of 12~22 kN, equivalent to applying a torque of 50~55 Nm to the thread. When replacing injectors 1 with different flow rates, it is necessary to determine if the ET pulse spectrum is suitable and calibrate the external characteristic fuel quantity as required. Each injector 1 configuration requires an external characteristic test to verify its power, economy, and emissions performance, and to make a preliminary comparison with development indicators and other configurations to determine if the deviation requirements are met, thus assessing whether further automatic calibration is necessary.
[0039] Optionally, in step S103, based on the optimal combination of injector flow rate, number of orifices, and orifice cone angle, the points are divided into emission area selection and non-emission area selection. When selecting emission area points, according to the definition of WNTE cycle control area, when clustering WHTC, the grid is divided and WHTC is clustered, removing operating conditions below 1000 rpm and below 0 Nm, clustering 10 operating condition points, and selecting 3 small torque points. For different engine models, the load rate of these 3 points can be increased accordingly to make the test and data stable and reliable, and facilitate the evaluation of the effect of post-vortex temperature on catalytic efficiency. When selecting non-emission area points, the low-speed full-load operating condition is selected as the feature point. The low-speed speed of the 4-cylinder engine is set to 1000 r / min, and the low-speed speed of the 6-cylinder engine is set to 800 r / min.
[0040] Optionally, in step S104, during processing, the target NOx emission is calculated based on the catalytic converter efficiency and original engine NOx emissions at each operating point, and the target NOx ratio for the final aftertreatment is calculated. Simultaneously, based on the prices of urea and diesel, the LCCE is calculated. The test data for each operating point are plotted, and the optimal LCCE result is obtained under the constraint conditions that the final NOx ratio, 415 smoke opacity, maximum knock pressure, and highest afterburner temperature meet the requirements. Specifically... ,in, This is the specific fuel consumption under this operating condition, expressed in g / kWh. This refers to the original engine emissions under this operating condition, expressed in g / kWh. This represents the target specific emissions under this operating condition, expressed in g / kWh. The price of Tilan is in yuan / L. The price of diesel fuel is expressed in yuan / L. The automatic calibration test data is exported as a standard template. The original engine NOx ratio, average catalyst temperature, and space velocity are calculated. Then, interpolation is performed using the catalyst limiting efficiency MAP to obtain the actual automatic calibration catalyst limiting efficiency under various operating conditions. Finally, a 3% margin is reserved based on the interpolated limiting efficiency. A 5% limit was set, and the engineering efficiency MAP was simulated to prevent ammonia leakage. Based on the catalyst limit efficiency and original NOx emissions at each operating point, the target NOx emission was calculated, and the target specific NOx of the final aftertreatment was calculated. The test data of each operating point were plotted, and the optimal LCCE result was obtained under the constraint conditions that the final specific NOx, 415 smoke opacity, maximum explosion pressure and highest after-vortex temperature meet the constraints.
[0041] In this embodiment, in step S600, the data is automatically calibrated, and a graph is drawn and compared with the final NOx emission ratio on the horizontal axis and LCCE, specific fuel consumption, 415 smoke opacity, explosion pressure, and in-vortex / out-of-vortex temperature on the vertical axis, and the optimal configuration scheme is selected.
[0042] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for matching the performance of a diesel engine injector, characterized in that: Includes the following steps: S101: Selection of injector structural parameters. These parameters include selection of injection air flow rate, number of injector orifices, and injector orifice cone angle. In selecting the fuel injection air flow rate, the formula for calculating the fuel injection air volume is: , This refers to the injector flow rate, expressed in L / min. The nozzle flow rate coefficient is... This represents the total cross-sectional area of the nozzle flow, in cm². 2 , This represents the pressure difference before and after the nozzle, expressed in MPa. Fuel density, in kg / m³ 3 For injectors with the same number of holes, cone angle, but different flow rates, select the best cone height based on the first set of injectors, and then select other injectors with different flow rates based on the best cone height. In selecting the number of injector holes, the formula for calculating the number of injector holes is as follows: ,in, This refers to the number of fuel injection holes. Eddy ratio, The injection duration angle is expressed in units of 1. For injectors with the same cone angle and flow rate but different numbers of holes, select the best cone height based on the first injector, and then select other injectors with different numbers of holes based on the best cone height. In the selection of injector nozzle cone angle, for injectors with the same flow rate and number of nozzles, different nozzle cone angles are selected. The optimal convex height is selected based on the first injector, and then other injectors with different nozzle cone angles are selected based on the optimal convex height. The nozzle cone angle is 140~160°. S102: Determination of the optimal structural parameters for the fuel injector design. S103: Selecting automatic calibration operating points based on the optimal solution. S104: Process the automatic calibration data according to the LCCE development goals. S105: Compare and select the best option to determine the final solution.
2. The diesel engine injector performance matching method according to claim 1, characterized in that: In step S102, based on the same external characteristics and maximum explosion pressure, the total power characteristics, load characteristics and propulsion characteristics of the diesel engine are tested. At the same time, the parameters of the injector are tested to confirm whether the injector capability meets the requirements. From the test data set, the optimal structural parameters of the injector scheme that meet the current configuration are selected, namely the best combination of injector flow rate, number of orifices and nozzle cone angle.
3. The diesel engine injector performance matching method according to claim 1, characterized in that: Step S103 includes selecting emission area points and non-emission area points. When selecting emission area points, the grid is divided and WHTC is clustered according to the definition of WNTE cycle control area. When selecting non-emission area points, the low-speed full-load condition is selected as the feature point. The low-speed speed of the 4-cylinder engine is set to 1000 r / min and the low-speed speed of the 6-cylinder engine is set to 800 r / min.
4. The diesel engine injector performance matching method according to claim 3, characterized in that: When performing clustering, WHTC selects three small torque points. For different models, the load rate of these three points can be increased accordingly to make the test and data stable and reliable, and facilitate the evaluation of the effect of the post-vortex temperature on catalytic efficiency.
5. The diesel engine injector performance matching method according to claim 1, characterized in that: During step S104, ,in, This is the specific fuel consumption under this operating condition, expressed in g / kWh. This refers to the original engine emissions under this operating condition, expressed in g / kWh. This represents the target specific emissions under this operating condition, expressed in g / kWh. The price of Tilan is in yuan / L. The price of diesel fuel is expressed in yuan / L. The automatic calibration test data is exported as a standard template. The original engine NOx ratio, average catalyst temperature, and space velocity are calculated. Then, interpolation is performed using the catalyst limiting efficiency MAP to obtain the actual automatic calibration catalyst limiting efficiency under various operating conditions. Finally, a 3% margin is reserved based on the interpolated limiting efficiency. A 5% limit was set, and the engineering efficiency MAP was simulated to prevent ammonia leakage. Based on the catalyst limit efficiency and original NOx emissions at each operating point, the target NOx emission was calculated, and the target specific NOx of the final aftertreatment was calculated. The test data of each operating point were plotted, and the optimal LCCE result was obtained under the constraint conditions that the final specific NOx, 415 smoke opacity, maximum explosion pressure and highest after-vortex temperature meet the constraints.
6. The diesel engine injector performance matching method according to claim 1, characterized in that: In step S600, the data is automatically calibrated and plotted with the final NOx emission ratio on the horizontal axis and LCCE, specific fuel consumption, 415 smoke opacity, explosion pressure, and in-vortex / out-vortex temperature on the vertical axis for comparison, and the optimal configuration scheme is selected.