Urea injection control method, device and equipment and storage medium

Abstract

The invention discloses a urea injection control method, device and equipment and a storage medium. The control method comprises the steps that the injection frequency, the required injection total amount, the maximum allowable injection duration and the nozzle flow-pulse width characteristic relation are obtained; determining a single urea spraying duration according to the spraying frequency, the required total spraying amount and the nozzle flow-pulse width characteristic relation; when the single-time urea spraying duration is smaller than or equal to the maximum allowable spraying duration, the urea nozzle is controlled to conduct spraying at the spraying frequency and the single-time urea spraying duration; and when the single-time urea spraying duration is larger than the maximum allowable spraying duration, the spraying frequency and the single-time urea spraying duration are adjusted. According to the technical scheme, the problem of crystallization caused by liquid drop collision or unstable spraying easily caused by traditional urea spraying control is solved, the risk of urea crystallization is reduced, and accurate control over urea spraying is achieved.

Description

Technical Field

[0001] This invention relates to the field of diesel engine exhaust aftertreatment technology, and in particular to a urea injection control method, device, equipment, and storage medium. Background Technology

[0002] Selective catalytic reduction (SCR) is a key technology for diesel engine exhaust treatment, but the crystallization of urea solution in the mixing chamber or exhaust pipe seriously affects system performance.

[0003] In existing technologies, urea injection control is mostly based on fixed parameters or simple feedback adjustment. For example, the injection volume is determined by looking up tables based on mixer temperature and air velocity, or the maximum injection volume is dynamically adjusted by temperature gradient. However, these methods do not fully consider the urea atomization time, leading to crystallization blockage under high load or low temperature conditions. For instance, when the duration of a single injection is too long, urea droplets may not be fully atomized before hitting the wall and solidifying, forming crystals. Furthermore, existing technologies lack a mechanism for synergistic optimization of injection frequency and duration, making it impossible to achieve precise control under complex operating conditions. Summary of the Invention

[0004] This invention provides a method, apparatus, device, and storage medium for controlling urea injection, to solve the problem that urea injection control in the prior art easily leads to crystallization due to wall collision, while achieving coordinated control of injection frequency and duration.

[0005] According to a first aspect of the present invention, a method for controlling urea injection is provided, comprising:

[0006] S10. Obtain the relationship between injection frequency, required total injection volume, maximum allowable injection duration, and nozzle flow-pulse width characteristics;

[0007] S11. Determine the duration of a single urea injection based on the injection frequency, the required total injection volume, and the relationship between the nozzle flow rate and pulse width characteristics.

[0008] S12. When the duration of a single urea injection is less than or equal to the maximum allowable injection duration, control the urea nozzle to inject at the injection frequency and the duration of a single urea injection.

[0009] S13. When the duration of a single urea injection is longer than the maximum permissible injection duration, adjust the injection frequency and the duration of a single urea injection.

[0010] Optionally, the injection frequency and duration of a single urea injection can be adjusted, including:

[0011] Adjust the injection frequency N0 from N0 = N to N0 = N + k, and adjust the required total injection volume M. i By M i =M i Change to M i=M i *(1+a%); where k≥1 and k is a positive integer; N≥1 and N is a positive integer; a is a constant;

[0012] Based on the injection frequency N0 and the required total injection volume M i The actual urea injection duration T0 is determined by the relationship between the nozzle flow rate and pulse width characteristics.

[0013] Obtain the minimum injection interval time and based on the minimum injection interval time T min The duration of a single urea injection, T, is determined by the actual urea injection duration, T0.

[0014] when If necessary, continue with step S12 or S13.

[0015] Optionally, the minimum spray interval time can be obtained, including:

[0016] Obtain the urea nozzle opening delay and urea nozzle closing delay;

[0017] The minimum injection interval time is determined based on the urea nozzle opening delay and the urea nozzle closing delay.

[0018] Optionally, obtain the minimum injection interval time and based on the minimum injection interval time T min After determining the duration T of a single urea injection based on the actual urea injection duration T0, the following steps are also included:

[0019] when At that time, the actual urea injection duration T0 is adjusted from T0=T0 to T0=T wall Among them, T wall This is the maximum permissible duration of spraying;

[0020] Based on the minimum injection interval T min The duration of a single urea injection, T, is determined by the actual urea injection duration, T0.

[0021] The injection frequency N is determined based on the duration T of a single urea injection.

[0022] Control the urea nozzle to inject at the adjusted injection frequency N and the duration of a single urea injection T.

[0023] Optionally, the injection frequency N and the duration T of a single urea injection satisfy the following relationship:

[0024] Optionally, obtain the injection frequency and required total injection volume, including:

[0025] Obtain exhaust gas flow rate, exhaust gas temperature, and post-treatment NO. X concentration;

[0026] Based on exhaust gas flow rate, exhaust gas temperature, and post-treatment NO X The concentration determines the required total spray volume and spray frequency.

[0027] Optionally, obtain the maximum permissible injection duration, including:

[0028] Obtain urea injection pressure, urea nozzle opening delay, urea nozzle closing delay, and mixing chamber cross-sectional area;

[0029] The maximum allowable injection duration is determined based on the urea injection pressure, urea nozzle opening delay, urea nozzle closing delay, and mixing chamber cross-sectional area.

[0030] According to a second aspect of the present invention, a urea injection control device is provided for performing a urea injection control method, the urea injection control device comprising:

[0031] The parameter acquisition module is used to acquire the injection frequency, required total injection volume, maximum allowable injection duration, and nozzle flow-pulse width characteristic relationship.

[0032] The injection time determination module is used to determine the duration of a single urea injection based on the injection frequency, the required total injection volume, and the nozzle flow-pulse width characteristic relationship.

[0033] The injection module is used to control the urea nozzle to spray at the injection frequency and the single urea injection duration when the duration of a single urea injection is less than or equal to the maximum allowable injection duration.

[0034] The injection adjustment module is used to adjust the injection frequency and the duration of a single urea injection when the duration of a single urea injection is longer than the maximum permissible injection duration.

[0035] According to a third aspect of the present invention, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement a method for controlling urea injection.

[0036] According to a fourth aspect of the present invention, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements a method for controlling urea injection.

[0037] The technical solution of this invention calculates the duration of a single urea injection and compares it with the maximum permissible injection duration. When the duration of a single urea injection is greater than the maximum permissible injection duration, the injection frequency and the duration of a single urea injection are dynamically adjusted. This solves the problem of crystallization caused by droplet collision or injection instability in traditional urea injection control, reduces the risk of urea crystallization, and achieves precise control of urea injection.

[0038] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a flowchart of a first urea injection control method provided according to an embodiment of the present invention;

[0041] Figure 2 This is a flowchart of a second urea injection control method provided according to an embodiment of the present invention;

[0042] Figure 3 This is a flowchart of a third urea injection control method provided according to an embodiment of the present invention;

[0043] Figure 4 This is a flowchart of a fourth urea injection control method provided according to an embodiment of the present invention;

[0044] Figure 5 This is a flowchart of the fifth urea injection control method provided in the embodiments of the present invention;

[0045] Figure 6 This is a flowchart of the sixth urea injection control method provided in the embodiments of the present invention;

[0046] Figure 7 This is a connection diagram of a urea injection control device according to an embodiment of the present invention;

[0047] Figure 8 This is a schematic diagram of an electronic device structure for a urea injection control method according to an embodiment of the present invention. Detailed Implementation

[0048] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0049] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0050] Figure 1 This is a flowchart of a first urea injection control method provided according to an embodiment of the present invention. Figure 1 As shown, the urea injection control method includes:

[0051] S10: Obtain the relationship between injection frequency, total injection volume required, maximum allowable injection duration, and nozzle flow-pulse width characteristics.

[0052] Among them, the injection frequency can be the number of times urea needs to be injected per unit time calculated based on the current exhaust gas conditions; the required total injection volume can be the total amount of urea to be injected calculated based on the current exhaust gas conditions; the maximum allowable injection duration can be the time when urea is precisely injected onto the wall of the mixing chamber, calculated based on the current urea injection pressure, urea nozzle characteristics, and mixing chamber cross-sectional area. This maximum allowable injection duration is intended to characterize that when injected within the maximum allowable injection duration, the uniformity of the injected urea is better and the risk of crystallization is lower. If the maximum allowable injection duration is exceeded, a large amount of urea may be injected onto the wall of the mixing chamber and crystallize before it is atomized; the nozzle flow rate-pulse width characteristic relationship can be the relationship between the pre-calibrated urea injection flow rate and the urea injection pulse width.

[0053] S11. Determine the duration of a single urea injection based on the injection frequency, the required total injection volume, and the relationship between nozzle flow rate and pulse width characteristics.

[0054] The duration of a single urea injection can be the duration of a single urea injection.

[0055] Specifically, the amount of urea injected per injection can be determined based on the injection frequency and the total amount of urea to be injected. The pulse width of a single urea injection can be determined based on the nozzle flow rate-pulse width characteristic relationship and the amount of urea injected per injection. The pulse width of a single urea injection is the duration of urea injection.

[0056] S12. When the duration of a single urea injection is less than or equal to the maximum allowable injection duration, control the urea nozzle to inject at the injection frequency and the duration of a single urea injection.

[0057] When the duration of a single urea injection is less than or equal to the maximum allowable injection duration, it indicates that the risk of crystallization is relatively low when injecting urea during the duration of a single injection. Therefore, the urea nozzle should be controlled to inject at the current injection frequency and pulse width of a single urea injection.

[0058] S13. When the duration of a single urea injection is longer than the maximum permissible injection duration, adjust the injection frequency and the duration of a single urea injection.

[0059] When the duration of a single urea injection is longer than the maximum permissible injection duration, it indicates that there is a risk of crystallization at the current injection frequency and the duration of a single urea injection. Therefore, the injection frequency and urea injection pulse width are adjusted.

[0060] Specifically, first obtain the injection frequency N0 = N and the required total injection volume M. i =M i Maximum permissible injection duration T wall The relationship between nozzle flow rate and pulse width characteristics; based on the injection frequency N0 = N and the required total injection volume M. i =M i The relationship between nozzle flow rate and pulse width characteristics determines the duration of a single urea injection, T = T; it also determines whether T ≤ T. wall At that time, the urea nozzle is controlled to spray at a spray frequency N0 = N and a single urea spray duration T = T; when it is determined that T > T wall At that time, adjust the injection frequency N0 and the duration of a single urea injection T, and repeat T and T. wall Comparative judgment.

[0061] It is understood that in this embodiment of the invention, only when the duration of a single urea injection is less than or equal to the maximum permissible injection duration, it is determined that the risk of crystallization is low when the injection frequency and pulse width of a single urea injection are used. Therefore, the urea nozzle is controlled to inject at the injection frequency and the duration of a single urea injection. Otherwise, the injection frequency and the duration of a single urea injection are readjusted to reduce the risk of crystallization due to wall collision, thereby achieving coordinated control of the injection frequency and the duration of the urea injection.

[0062] The technical solution of this invention calculates the duration of a single urea injection and compares it with the maximum permissible injection duration. When the duration of a single urea injection is greater than the maximum permissible injection duration, the injection frequency and the duration of a single urea injection are dynamically adjusted. This solves the problem of crystallization caused by droplet collision or injection instability in traditional urea injection control, reduces the risk of urea crystallization, and achieves precise control of urea injection.

[0063] Based on the above embodiments, Figure 2 This is a flowchart of a second urea injection control method provided according to an embodiment of the present invention, as shown below. Figure 2 As shown, the control method includes:

[0064] S20: Obtain the relationship between injection frequency, required total injection volume, maximum allowable injection duration, and nozzle flow-pulse width characteristics.

[0065] S21. Determine the duration of a single urea injection based on the injection frequency, the required total injection volume, and the relationship between nozzle flow rate and pulse width characteristics.

[0066] S22. When the duration of a single urea injection is less than or equal to the maximum allowable injection duration, control the urea nozzle to inject at the injection frequency and the duration of a single urea injection.

[0067] S23. When the duration of a single urea injection exceeds the maximum permissible injection duration, adjust the injection frequency N0 from N0 = N to N0 = N + k, and adjust the required total injection volume M. i By M i =M i Change to M i =M i *(1+a%). Where k≥1 and k is a positive integer; N≥1 and N is a positive integer; a is a constant.

[0068] When there is a risk of crystallization when spraying urea at the current spray frequency and with a single spray duration, the spray frequency N0 is adjusted from N0 = N to N0 = N + k, i.e., the urea spray frequency is increased to achieve multiple sprays of urea, thereby reducing the amount sprayed per spray, decreasing the probability of urea hitting the walls of the mixing chamber, and reducing the risk of crystallization. However, in practical applications, increasing the spray frequency often leads to a decrease in the actual total spray volume, resulting in a decrease in spraying effect. To avoid insufficient single spray volume after increasing the spray frequency, the technical solution of this embodiment adjusts the required total spray volume M by increasing the required total spray volume. i By M i =M i Change to M i =M i *(1+a%) means increasing the urea injection volume so that the actual total injection volume corresponding to the high injection frequency is close to the actual total injection volume corresponding to the low injection frequency, in order to ensure the exhaust gas treatment effect.

[0069] In some embodiments, 1% ≤ a% ≤ 5% is set to correct the urea injection volume.

[0070] S24. Based on the injection frequency N0 and the required total injection volume M... iThe actual urea injection duration T0 is determined by the relationship between the nozzle flow rate and pulse width characteristics.

[0071] Among them, the injection frequency N0 and the required total injection volume M i After adjustment, the actual urea injection duration T0 is calculated by combining the nozzle flow rate-pulse width characteristic relationship. The actual urea injection duration T0 can be calculated based on N0 = N + k, M i =M i *(1+a%), the duration of a single urea injection calculated from the nozzle flow-pulse width characteristic relationship.

[0072] S25, Obtain the minimum injection interval time and based on the minimum injection interval time T min The duration of a single urea injection, T, is determined by the actual urea injection duration, T0.

[0073] The minimum injection interval time can be defined as the minimum interval between two adjacent injections, taking into account the urea nozzle control delay time. Based on the minimum injection interval time T... min The duration of a single urea injection, T, can be calculated from the actual urea injection duration T0. Among these, the minimum injection interval T... min The duration of a single urea injection, T, and the actual duration of urea injection, T0, satisfy the condition T = T min +T0 is used to ensure stable urea injection.

[0074] S26, when If necessary, continue with step S22 or S23.

[0075] Among these, while ensuring stable urea injection, the relationship between N0*T and... The relationship between them is given by N0*T, where N0*T represents the total time required under the current injection frequency and stable injection time. This can represent the injection cycle calculated based on the current exhaust gas conditions, therefore when When this occurs, it indicates that multiple injections can be completed within a single injection cycle. Therefore, we continue to determine the relationship between the duration of a single urea injection and the maximum permissible injection duration, where T ≤ T wall When executing step S22, control the urea nozzle to achieve an injection frequency of N0 = N + k and a single urea injection duration of T = T. min +T0 initiates injection; when T>T wall At that time, continue to adjust the injection frequency N0 and the duration T of a single urea injection and recalculate and judge, and then close the loop.

[0076] For example, if k=1, then when T>T wall At that time, the injection frequency N0 is adjusted from N0=N to N0=N+1, and the required total injection volume M is adjusted accordingly. i By Mi =M i Change to M i =M i *(1+a%); Based on the injection frequency N0 and the required total injection volume M i The actual urea injection duration T0 is determined by the relationship between nozzle flow rate and pulse width characteristics, and the minimum injection interval T is used as a basis. min The duration of a single urea injection, T = T0, is determined by the actual urea injection duration T0. min +T0, because the product of the injection frequency and the duration of a single urea injection must be less than the injection cycle, therefore... Then, continue to judge T and T wall The size relationship between them, if T≤T wall Execute step S22 to control the urea nozzle with an injection frequency N0 = N + k and a single urea injection duration T = T min +T0 is used for injection, T>T wall If necessary, continue to adjust the injection frequency N0 and the duration of a single urea injection T, and recalculate and judge.

[0077] The technical solution of this invention dynamically adjusts the injection frequency and the duration of a single urea injection when the duration of a single urea injection is longer than the maximum permissible injection duration. This increases the injection frequency and realizes an adaptive adjustment mechanism, which solves the crystallization problem caused by droplet collision or injection instability that is easily caused by traditional urea injection control. This reduces the risk of urea crystallization and achieves precise control of urea injection.

[0078] Based on the above embodiments, Figure 3 This is a flowchart of a third urea injection control method provided according to an embodiment of the present invention, as shown below. Figure 3 As shown, the control method includes:

[0079] S30: Obtain the relationship between injection frequency, required total injection volume, maximum allowable injection duration, and nozzle flow-pulse width characteristics.

[0080] S31. Determine the duration of a single urea injection based on the injection frequency, the required total injection volume, and the relationship between nozzle flow rate and pulse width characteristics.

[0081] S32. When the duration of a single urea injection is less than or equal to the maximum allowable injection duration, control the urea nozzle to inject at the injection frequency and the duration of a single urea injection.

[0082] S33. When the duration of a single urea injection exceeds the maximum permissible injection duration, adjust the injection frequency N0 from N0 = N to N0 = N + k, and adjust the required total injection volume M. i By M i =M i Change to M i=M i *(1+a%). Where k≥1 and k is a positive integer; N≥1 and N is a positive integer; a is a constant.

[0083] S34. Based on the injection frequency N0 and the required total injection volume M i The actual urea injection duration T0 is determined by the relationship between the nozzle flow rate and pulse width characteristics.

[0084] S35. Obtain the urea nozzle opening delay and urea nozzle closing delay.

[0085] S36. Determine the minimum injection interval time based on the urea nozzle opening delay and the urea nozzle closing delay, and then determine the minimum injection interval time T based on the minimum injection interval time T. min The duration of a single urea injection, T, is determined by the actual urea injection duration, T0.

[0086] In this invention, when the system controls the hardware device, there is an inevitable delay in control time due to the sensitivity of the hardware device. Therefore, this embodiment of the invention obtains the urea nozzle opening delay and the urea nozzle closing delay, and determines the minimum injection interval time based on the urea nozzle opening delay and the urea nozzle closing delay to ensure the stable operation of the urea nozzle.

[0087] S37, when If necessary, continue with step S32 or S33.

[0088] Based on the above embodiments, Figure 4 This is a flowchart of a fourth urea injection control method provided according to an embodiment of the present invention, as shown below. Figure 4 As shown, the control method includes:

[0089] S40: Obtain the relationship between injection frequency, required total injection volume, maximum allowable injection duration, and nozzle flow-pulse width characteristics.

[0090] S41. Determine the duration of a single urea injection based on the injection frequency, the required total injection volume, and the relationship between nozzle flow rate and pulse width characteristics.

[0091] S42. When the duration of a single urea injection is less than or equal to the maximum allowable injection duration, control the urea nozzle to inject at the injection frequency and the duration of a single urea injection.

[0092] S43. When the duration of a single urea injection exceeds the maximum permissible injection duration, adjust the injection frequency N0 from N0 = N to N0 = N + k, and adjust the required total injection volume M. i By M i =M i Change to M i =M i*(1+a%). Where k≥1 and k is a positive integer; N≥1 and N is a positive integer; a is a constant.

[0093] S44. Based on the injection frequency N0 and the required total injection volume M... i The actual urea injection duration T0 is determined by the relationship between the nozzle flow rate and pulse width characteristics.

[0094] S45, Obtain the minimum injection interval time and based on the minimum injection interval time T min The duration of a single urea injection, T, is determined by the actual urea injection duration, T0.

[0095] S46, when If necessary, continue with step S42 or S43.

[0096] S47, when At that time, the actual urea injection duration T0 is adjusted from T0=T0 to T0=T wall Among them, T wall This is the maximum permissible spray duration.

[0097] Among them, when This indicates that multiple injections cannot be implemented within the injection cycle at this time. Therefore, to avoid abnormal crystallization, a limit protection setting is implemented for the duration of a single urea injection. Thus, the actual urea injection duration T0 is adjusted from T0 = T0 to T0 = T wall This ensures that the actual urea injection duration is the same as the maximum permissible injection duration.

[0098] S48, Based on the minimum spray interval time T min The duration of a single urea injection, T, is determined by the actual urea injection duration, T0.

[0099] Among them, continue according to T0=T wall Combined with minimum injection interval time T min Calculate the duration T of a single urea injection under stable injection conditions. The duration T of a single urea injection is T = T wall +T min .

[0100] S491. Determine the injection frequency N based on the duration T of a single urea injection.

[0101] The maximum injection frequency N can be calculated based on the duration T of a single urea injection. In some embodiments, the injection frequency N and the duration T of a single urea injection satisfy the following relationship: Then calculate right Round down to the nearest integer.

[0102] S492. Control the urea nozzle to inject at the adjusted injection frequency N and the duration of a single urea injection T.

[0103] Among them, with T = T wall +T min Controlling urea injection prevents urea from crystallizing on the walls of the mixing chamber before it is atomized, ensuring the stability of the system under extreme conditions.

[0104] The technical solution of this invention embodiment, in determining The system provides limit protection for the duration of a single urea injection, forcibly setting the actual urea injection duration as the maximum allowable injection duration to ensure limit injection under extreme working conditions and avoid uncontrolled injection parameters due to poor timing control and nozzle stability.

[0105] Based on the above embodiments, Figure 5 This is a flowchart of the fifth urea injection control method provided by an embodiment of the present invention, as shown below. Figure 5 As shown, the control method includes:

[0106] S50, obtain exhaust gas flow rate, exhaust gas temperature and post-treatment NO. X Relationship between concentration, maximum allowable injection duration, and nozzle flow-pulse width characteristics.

[0107] Among them, the exhaust gas flow rate can be the exhaust gas flow rate collected upstream of the Selective Catalytic Reduction (SCR) system; the exhaust gas temperature can be the exhaust gas temperature collected inside the SCR system; and the post-treatment NO... X The concentration can be the NO at the inlet of the SCR system post-treatment. X concentration.

[0108] S51, based on exhaust gas flow rate, exhaust gas temperature, and post-treatment NO... X The concentration determines the required total spray volume and spray frequency.

[0109] Among them, based on exhaust gas flow rate, exhaust gas temperature and post-treatment NO X The concentration can be used to calculate the required total injection volume and injection frequency of the current SCR system, which can ensure the purification effect of the exhaust gas under the required total injection volume and injection frequency.

[0110] S52. Determine the duration of a single urea injection based on the injection frequency, the required total injection volume, and the relationship between nozzle flow rate and pulse width characteristics.

[0111] S53. When the duration of a single urea injection is less than or equal to the maximum allowable injection duration, control the urea nozzle to inject at the injection frequency and the duration of a single urea injection.

[0112] S54. When the duration of a single urea injection is longer than the maximum permissible injection duration, adjust the injection frequency and the duration of a single urea injection.

[0113] The technical solution of this invention involves obtaining waste gas flow rate, waste gas temperature, and post-treatment NO. X Determining the concentration requires the total injection volume and injection frequency. Ensuring the accuracy of these determinations helps improve the precision of SCR system control.

[0114] Based on the above embodiments, Figure 6 This is a flowchart of the sixth urea injection control method provided by an embodiment of the present invention, as shown below. Figure 6 As shown, the control method includes:

[0115] S60, obtain the relationship between urea injection pressure, urea nozzle opening delay, urea nozzle closing delay, mixing chamber cross-sectional area, injection frequency, required total injection volume, and nozzle flow-pulse width characteristics.

[0116] The cross-sectional area of ​​the mixing chamber can be the axial tangential area of ​​the mixing chamber; the urea nozzle opening delay and urea nozzle closing delay can be the response delay time for controlling the opening and closing of the urea nozzle.

[0117] S61. Determine the maximum allowable injection duration based on the urea injection pressure, urea nozzle opening delay, urea nozzle closing delay, and mixing chamber cross-sectional area.

[0118] The cross-sectional area of ​​the mixing chamber can measure the position of urea injection into the mixing chamber, which includes the position inside the mixing chamber and the wall of the mixing chamber. The opening delay and closing delay of the urea nozzle can measure the response delay time of controlling the opening and closing of the urea nozzle. Therefore, based on the urea injection pressure, the opening delay of the urea nozzle, the closing delay of the urea nozzle, and the cross-sectional area of ​​the mixing chamber, the duration of urea injection that just hits the wall under the current exhaust gas flow rate, exhaust gas temperature, and urea injection pressure can be calculated, which is the maximum allowable injection duration.

[0119] S62. Determine the duration of a single urea injection based on the injection frequency, the required total injection volume, and the relationship between nozzle flow rate and pulse width characteristics.

[0120] S63. When the duration of a single urea injection is less than or equal to the maximum allowable injection duration, control the urea nozzle to inject at the injection frequency and the duration of a single urea injection.

[0121] S64. When the duration of a single urea injection is longer than the maximum permissible injection duration, adjust the injection frequency and the duration of a single urea injection.

[0122] It is understandable that by combining the geometric parameters of the mixing chamber with the nozzle response characteristics, constraints on the maximum duration of crystallization spray can be established to ensure that the single spray time is within the physical limit.

[0123] The technical solution of this invention fully considers the urea atomization time and the structural parameters of the mixing chamber. By introducing geometric constraints of the mixing chamber and nozzle response characteristics, it realizes closed-loop optimization of the urea injection strategy, fundamentally reducing the risk of urea crystallization. It solves the problem that traditional urea injection control relies solely on the single variable of adjusting the urea injection duration, which easily leads to crystallization caused by droplet collision or injection instability.

[0124] Based on the same inventive concept. Figure 7 This is a connection diagram of a urea injection control device according to an embodiment of the present invention, as shown below. Figure 7 As shown, this embodiment of the invention provides a urea injection control device for executing a urea injection control method. The urea injection control device includes:

[0125] The parameter acquisition module 100 is used to acquire the injection frequency, required total injection volume, maximum allowable injection duration, and nozzle flow-pulse width characteristic relationship.

[0126] The injection time determination module 200 is used to determine the duration of a single urea injection based on the injection frequency, the required total injection volume, and the relationship between the nozzle flow rate and pulse width characteristics.

[0127] The injection module 300 is used to control the urea nozzle to spray at the injection frequency and the duration of a single urea injection when the duration of a single urea injection is less than or equal to the maximum allowable injection duration.

[0128] The injection adjustment module 400 is used to adjust the injection frequency and the duration of a single urea injection when the duration of a single urea injection is longer than the maximum permissible injection duration.

[0129] The technical solution of this invention combines a parameter acquisition module, an injection time determination module, an injection module, and an injection adjustment module to dynamically adjust the injection frequency and the duration of a single urea injection when the duration of a single urea injection is longer than the maximum permissible injection duration. This solves the crystallization problem caused by droplet collision or injection instability in traditional urea injection control, reduces the risk of urea crystallization, and achieves precise control of urea injection.

[0130] Based on the same inventive concept, embodiments of the present invention also provide a computer device. Figure 8 This is a schematic diagram of an electronic device structure for a urea injection control method according to an embodiment of the present invention, as shown below. Figure 8As shown, it includes a memory, a processor, and a computer program stored in the memory and capable of running on the processor. When the processor executes the program, it implements a method for controlling urea injection.

[0131] The term "electronic device" is intended to refer to various forms of digital computers, such as laptop computers, desktop computers, workstations, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. Electronic devices can also refer to various forms of mobile devices, such as personal digital processors, cellular phones, smartphones, wearable devices (e.g., helmets, glasses, watches), and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely illustrative and are not intended to limit the implementation of the invention described and / or claimed herein.

[0132] like Figure 8 As shown, the electronic device 50 includes at least one processor 51 and a memory, such as a read-only memory (ROM) 52 and a random access memory (RAM) 53, communicatively connected to the at least one processor 51. The memory stores computer programs executable by the at least one processor. The processor 51 can perform various appropriate actions and processes based on the computer program stored in the ROM 52 or loaded into the RAM 53 from storage unit 58. The RAM 53 can also store various programs and data required for the operation of the electronic device 50. The processor 51, ROM 52, and RAM 53 are interconnected via a bus 54. An input / output (I / O) interface 55 is also connected to the bus 54.

[0133] Multiple components in electronic device 50 are connected to I / O interface 55, including: input unit 56, such as keyboard, mouse, etc.; output unit 57, such as various types of monitors, speakers, etc.; storage unit 58, such as disk, optical disk, etc.; and communication unit 59, such as network card, modem, wireless transceiver, etc. Communication unit 59 allows electronic device 50 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0134] Processor 51 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 51 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 51 performs the various methods and processes described above, such as control methods applied to urea injection.

[0135] Based on the same inventive concept, embodiments of the present invention also provide a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements a method for controlling urea injection.

[0136] Of course, the computer-readable storage medium provided in the embodiments of the present invention has computer-executable instructions that are not limited to the method operations described above, but can also execute related operations in the urea injection control method provided in any embodiment of the present invention. (Continue to refer to...) Figure 8 As shown, it is tangibly contained in a computer-readable storage medium, such as storage unit 58. In some embodiments, part or all of the computer program may be loaded and / or mounted on electronic device 50 via ROM 52 and / or communication unit 59. When the computer program is loaded into RAM 53 and executed by processor 51, one or more steps of the control method for urea injection described above may be performed. Alternatively, in other embodiments, processor 51 may be configured to perform the control method for urea injection by any other suitable means (e.g., by means of firmware).

[0137] Various embodiments of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field-programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), systems-on-a-chip (SoCs), payload-programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various embodiments may include implementations in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which may be a dedicated or general-purpose programmable processor, capable of receiving data and instructions from a storage system, at least one input device, and at least one output device, and transmitting data and instructions to the storage system, the at least one input device, and the at least one output device.

[0138] Computer programs used to implement the methods of the present invention may be written in any combination of one or more programming languages. These computer programs may be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, such that when executed by the processor, the computer programs cause the functions / operations specified in the flowcharts and / or block diagrams to be performed. The computer programs may be executed entirely on a machine, partially on a machine, or as a standalone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0139] In the context of embodiments of the present invention, a computer-readable storage medium may be a tangible medium that may contain or store a computer program for use by or in conjunction with an instruction execution system, apparatus, or device. A computer-readable storage medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination of the foregoing. Alternatively, a computer-readable storage medium may be a machine-readable signal medium. More specific examples of machine-readable storage media include electrical connections based on one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0140] To provide interaction with a user, the systems and techniques described herein can be implemented on an electronic device having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user provides input to the electronic device. Other types of devices can also be used to provide interaction with the user; for example, feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including sound input, voice input, or tactile input).

[0141] The systems and technologies described herein can be implemented in computing systems that include backend components (e.g., as data servers), or computing systems that include middleware components (e.g., application servers), or computing systems that include frontend components (e.g., user computers with graphical user interfaces or web browsers through which users can interact with implementations of the systems and technologies described herein), or any combination of such backend, middleware, or frontend components. The components of the system can be interconnected via digital data communication of any form or medium (e.g., communication networks). Examples of communication networks include local area networks (LANs), wide area networks (WANs), blockchain networks, and the Internet.

[0142] A computing system can include clients and servers. Clients and servers are generally located far apart and typically interact through communication networks. The client-server relationship is created by computer programs running on the respective computers and having a client-server relationship with each other. The server can be a cloud server, also known as a cloud computing server or cloud host, which is a hosting product within the cloud computing service system to address the shortcomings of traditional physical hosts and VPS services, such as high management difficulty and weak business scalability.

[0143] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0144] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for controlling urea injection, characterized in that, include: S10. Obtain the relationship between injection frequency, required total injection volume, maximum allowable injection duration, and nozzle flow-pulse width characteristics; S11. Determine the duration of a single urea injection based on the injection frequency, the required total injection volume, and the nozzle flow rate-pulse width characteristic relationship. S12. When the duration of a single urea injection is less than or equal to the maximum allowable injection duration, control the urea nozzle to inject at the injection frequency and the duration of a single urea injection. S13. When the duration of a single urea injection is greater than the maximum permissible injection duration, adjust the injection frequency and the duration of a single urea injection.

2. The control method according to claim 1, characterized in that, Adjusting the injection frequency and the duration of a single urea injection includes: Adjust the injection frequency N0 from N0 = N to N0 = N + k, and adjust the required total injection volume M. i By M i =M i Change to M i =M i *(1+a%); where k≥1 and k is a positive integer; N≥1 and N is a positive integer; a is a constant; Based on the injection frequency N0 and the required total injection volume M i The actual urea injection duration T0 is determined by the relationship between the nozzle flow rate and pulse width characteristics. Obtain the minimum injection interval time and according to the minimum injection interval time T min The duration of a single urea injection, T, is determined by the actual urea injection duration, T0. when If necessary, continue with step S12 or S13.

3. The control method according to claim 2, characterized in that, To obtain the minimum injection interval time, including: Obtain the urea nozzle opening delay and urea nozzle closing delay; The minimum injection interval time is determined based on the urea nozzle opening delay and the urea nozzle closing delay.

4. The control method according to claim 2, characterized in that, Obtain the minimum injection interval time and according to the minimum injection interval time T min After determining the duration T of a single urea injection based on the actual urea injection duration T0, the following steps are also included: when At that time, the actual urea injection duration T0 is adjusted from T0 = T0 to T0 = T wall Among them, T wall This refers to the maximum permissible spray duration; According to the minimum injection interval time T min The duration of a single urea injection, T, is determined by the actual urea injection duration, T0. The injection frequency N is determined based on the duration T of a single urea injection. The urea nozzle is controlled to adjust the injection frequency N and the duration of a single urea injection T.

5. The control method according to claim 4, characterized in that, The injection frequency N and the duration of a single urea injection T satisfy the following relationship:

6. The control method according to claim 1, characterized in that, Obtain the injection frequency and required total injection volume, including: Obtain exhaust gas flow rate, exhaust gas temperature, and post-treatment NO. X concentration; Based on the exhaust gas flow rate, the exhaust gas temperature, and the post-treatment NO... X The concentration determines the required total spray volume and spray frequency.

7. The control method according to claim 1, characterized in that, To obtain the maximum permissible injection duration, including: Obtain urea injection pressure, urea nozzle opening delay, urea nozzle closing delay, and mixing chamber cross-sectional area; The maximum permissible injection duration is determined based on the urea injection pressure, the urea nozzle opening delay, the urea nozzle closing delay, and the cross-sectional area of ​​the mixing chamber.

8. A urea injection control device, characterized in that, A control device for performing the urea injection control method according to any one of claims 1-7, comprising: The parameter acquisition module is used to acquire the injection frequency, required total injection volume, maximum allowable injection duration, and nozzle flow-pulse width characteristic relationship. The injection time determination module is used to determine the duration of a single urea injection based on the injection frequency, the required total injection volume, and the nozzle flow rate-pulse width characteristic relationship. The injection module is used to control the urea nozzle to inject at the injection frequency and the single urea injection duration when the duration of a single urea injection is less than or equal to the maximum allowable injection duration. The injection adjustment module is used to adjust the injection frequency and the duration of a single urea injection when the duration of a single urea injection is greater than the maximum permissible injection duration.

9. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the control method as described in any one of claims 1-7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the control method as described in any one of claims 1-7.

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