Method for controlling heating of a methanol heating nozzle, methanol heating nozzle and engine

Abstract

The present application relates to the technical field of engine, and particularly discloses a heating control method of a methanol heating nozzle, the methanol heating nozzle and an engine. The heating control method of the methanol heating nozzle adjusts the heating power of the nozzle according to the change rate of the nitrogen oxide content, realizes the control of the heating power of the nozzle in the cold start stage of the engine, adjusts the heating power of the nozzle according to the knock signal of the knock sensor and the actual heating temperature, realizes the control of the heating power of the nozzle in the engine body temperature rising stage and the engine warm-up stage, and avoids the continuous or long-time knock. The heating power of the nozzle is adjusted through the nitrogen oxide content and the change rate of the nitrogen oxide content and the knock sensor signal and the actual heating temperature of the nozzle in the cold start stage to the warm-up running stage of the engine, so that the control is not dependent on the intake air temperature, and the problem of high response delay of the nozzle heating power adjustment caused by the heat transfer time between the heating element and the mixture is effectively solved.

Description

Technical Field

[0001] This invention relates to the field of engine technology, and in particular to a heating control method for a methanol heating nozzle, a methanol heating nozzle, and an engine. Background Technology

[0002] Cold starts of methanol engines are challenging at low temperatures. Without additional preheating or heating measures, an ambient temperature drop to 15°C can make cold starts difficult. Current technologies typically employ methods such as altering the fuel composition, intake air heating, fuel heating, and auxiliary fuel starting. Considering system complexity and overall cost control, intake air heating is generally used to improve cold start performance.

[0003] However, the demand for auxiliary heating varies under different operating conditions. During cold starts at low temperatures, the cylinder temperature is low, methanol evaporation is poor, and combustion is unsatisfactory, requiring a higher heating temperature. The demand for auxiliary heating also varies with engine speed and load. Under low load, the cylinder temperature is low, methanol evaporation is poor, and combustion conditions are harsh, requiring an even higher heating temperature. As the overall engine temperature rises and combustion gradually improves, using a higher auxiliary heating temperature at this point would accelerate the combustion process, leading to knocking. Therefore, it is necessary to dynamically control the heating power to adapt to the heating requirements under different operating conditions. However, the intake air temperature after heating cannot be directly measured; it can only be measured by the heating element. The heat transfer from the heating element to the intake air or fuel takes time, resulting in a significant delay in the adjustment response of the heating power, making knocking more likely and lasting longer. Summary of the Invention

[0004] The purpose of this invention is to provide a heating control method for a methanol heating nozzle, a methanol heating nozzle, and an engine, in order to solve the problem of high adjustment response delay of heating power in related technologies.

[0005] This invention provides a heating control method for a methanol heating nozzle, comprising: S1. Obtain the nitrogen oxide content in the exhaust gas, and determine the engine status as cold start, cold engine, or warm-up based on the nitrogen oxide content. If the engine status is cold engine, proceed to step S2. S2. The methanol heating nozzle heats at maximum power to continuously obtain the nitrogen oxide content in the exhaust gas until the nitrogen oxide content change rate is ≤0 for a preset time, and then proceed to step S3. S3. Obtain the knock signal from the knock sensor, adjust the heating power of the nozzle according to the knock signal, and execute step S4. S4. Adjust the nozzle heating power according to the actual heating temperature of the nozzle.

[0006] As a preferred technical solution for the heating control method of the methanol heating nozzle, step S1 includes: Continuously obtain the content of nitrogen oxides; If the nitrogen oxide content is greater than the preset value, the engine is in a cold state and step S2 is executed; otherwise, the engine is in a cold start state and the nozzle is heated at maximum power.

[0007] As a preferred technical solution for the heating control method of the methanol heating nozzle, step S2 includes: Continuously monitor the rate of change in nitrogen oxides; Determine if the rate of change of nitrogen oxides is ≤0; If the rate of change of nitrogen oxides is ≤0, then continue to determine whether the rate of change of nitrogen oxides remains ≤0 within a preset time; otherwise, the nozzle heats at maximum power. If the rate of change of nitrogen oxides remains ≤0 within a preset time, the heating power of the nozzle is reduced and step S3 is executed; otherwise, the nozzle is heated at maximum power.

[0008] As a preferred technical solution for the heating control method of the methanol heating nozzle, step S3 includes: Continuously monitor whether the knock sensor emits a knock signal; If the knock sensor emits a knock signal, reduce the nozzle heating power; otherwise, maintain the current nozzle heating power and proceed to step S4.

[0009] As a preferred technical solution for the heating control method of the methanol heating nozzle, step S4 includes: Obtain the actual heating temperature T of the nozzle, and obtain the required heating temperature T0; If T=T0, then the nozzle heating power remains unchanged; If T > T0, then reduce the nozzle heating power; If T < T0, increase the nozzle heating power and return to step S3.

[0010] As a preferred technical solution for the heating control method of the methanol heating nozzle, the required heating temperature T0 is taken from the required heating temperature range (T... 0i ,T 0a ).

[0011] As a preferred technical solution for the heating control method of the methanol heating nozzle, the method further includes the following step before step S1: The nozzle is heated at maximum power for a preheating time before fuel is injected.

[0012] This invention provides a methanol heating nozzle and a heating control method for executing any of the above-described schemes of the methanol heating nozzle, wherein the methanol heating nozzle comprises: A valve body and a valve needle, the valve needle being slidably disposed within the valve body to open or close the fuel passage; A heating component is sleeved outside the valve body and is capable of heating the valve body.

[0013] As a preferred technical solution for a methanol heating nozzle, the heating assembly includes a cylinder and a heating element. One end of the cylinder is provided with a receiving groove, which is continuous along the circumference of the cylinder. The heating element is disposed in the receiving groove, and the inner wall of the cylinder is in contact with the outer wall of the end of the valve body where the nozzle is disposed.

[0014] The present invention provides a methanol engine, a heating control method for a methanol heating nozzle using any of the above-described solutions, or a methanol heating nozzle including any of the above-described solutions.

[0015] The beneficial effects of this invention are as follows: This invention provides a heating control method for a methanol heating nozzle. The method determines the engine's state by the nitrogen oxide (NOx) content and adjusts the nozzle's heating power based on the rate of change in NOx content. This achieves control of the nozzle's heating power during the engine cold start phase. Furthermore, it adjusts the nozzle's heating power based on the knock signal from the knock sensor and the actual heating temperature, enabling control during the engine body temperature rise and warm-up phases, while simultaneously preventing continuous or prolonged knocking. This method achieves nozzle heating power adjustment sequentially from engine cold start to warm-up operation based on NOx content, the rate of change in NOx content, the knock sensor signal, and the actual nozzle heating temperature, thus achieving control independent of intake air temperature. It also effectively solves the problem of high response delay in nozzle heating power adjustment caused by the time-consuming heat transfer between the heating element and the air-fuel mixture.

[0016] This invention provides a methanol heating nozzle. By implementing the heating control method of the methanol heating nozzle in this invention, the heating control of the methanol heating nozzle is made more precise.

[0017] This invention provides an engine in which the low-temperature cold start performance of a methanol engine is improved by using the heating control method of the methanol heating nozzle of this invention or by setting the methanol heating nozzle of this invention, while suppressing knock tendency and reducing knock duration to a certain extent. Attached Figure Description

[0018] Figure 1 This is a flowchart of the heating control method for the methanol heating nozzle in an embodiment of the present invention; Figure 2 This is a flowchart illustrating the adjustment of the nozzle heating state based on the nitrogen oxide content in an embodiment of the present invention. Figure 3This is a flowchart illustrating the adjustment of nozzle heating power based on the rate of change of nitrogen oxide content in an embodiment of the present invention. Figure 4 This is a flowchart illustrating the adjustment of nozzle heating power based on the detonation signal from the detonation sensor in an embodiment of the present invention. Figure 5 This is a flowchart illustrating the adjustment of nozzle heating power based on the actual heating temperature of the nozzle in an embodiment of the present invention. Figure 6 This is a cross-sectional view of the nozzle in an embodiment of the present invention; Figure 7 This is a cross-sectional view of the heating sleeve in an embodiment of the present invention.

[0019] In the picture: 1. Valve body; 2. Screw sleeve; 3. Cylinder; 4. Heating element; 5. Snap ring. Detailed Implementation

[0020] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] 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. They are used only for the convenience of describing the invention and for 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions. Furthermore, "above," "on top of," and "over" the first feature in relation to the second feature includes the first feature directly above and diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "under," and "below" the first feature in relation to the second feature includes the first feature directly below and diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0022] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" 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 according to the specific circumstances.

[0023] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0024] like Figures 1-5 As shown, this embodiment of the invention provides a heating control method for a methanol heating nozzle, applied to the heating control of a methanol heating nozzle in a methanol fuel engine. The heating control method for the methanol heating nozzle includes the following steps: S1. Obtain the nitrogen oxide content in the exhaust gas, and determine the engine status as cold start, cold engine, or warm-up based on the nitrogen oxide content. If the engine status is cold engine, proceed to step S2. S2. The methanol heating nozzle heats at maximum power to continuously obtain the nitrogen oxide content in the exhaust gas until the nitrogen oxide content change rate is ≤0 for a preset time, and then proceed to step S3. S3. Obtain the knock signal from the knock sensor, adjust the heating power of the nozzle according to the knock signal, and execute step S4. S4. Adjust the nozzle heating power according to the actual heating temperature of the nozzle.

[0025] An engine's transition from a cold start at a low temperature to normal operation involves three phases: cold start, cold engine, and warm-up. During the cold start phase, the engine block and related fluid temperatures are low, and the nitrogen oxide (NOx) content in the exhaust gas does not increase significantly for a short period after startup. Subsequently, as the engine block and fluid temperatures gradually rise, the NOx content in the exhaust gas increases to a certain level, marking the engine's cold start phase. However, the combustion efficiency at this stage is still not as high as in the warm-up phase. Therefore, the engine's state is determined by the NOx content, and the nozzle heating power is adjusted based on the rate of change in NOx content. This controls the nozzle heating power during the cold start phase. Furthermore, the nozzle heating power is adjusted based on the knock signal from the knock sensor and the actual heating temperature to control the nozzle heating power during the engine block temperature rise and warm-up phases, while simultaneously preventing continuous or prolonged knocking. This method allows for the adjustment of nozzle heating power during the engine's cold start-up and warm-up phases, based on nitrogen oxide content, nitrogen oxide content change rate, knock sensor signal, and actual nozzle heating temperature. This eliminates reliance on intake air temperature for control and effectively solves the problem of high response delay in nozzle heating power adjustment caused by the time-consuming heat transfer between the heating element and the air-fuel mixture. The nozzle heating power can be adjusted via the supply current or the duty cycle of the PWM wave; no specific limitation is specified here.

[0026] Specifically, such as Figure 2 As shown, during the engine's low-temperature cold start phase, the engine block temperature is low, and the air-fuel mixture burns poorly. At this time, the exhaust gas does not contain nitrogen oxides or has a low nitrogen oxide content. Therefore, step S1 includes: Continuously obtain the content of nitrogen oxides; If the nitrogen oxide content is greater than the preset value, the engine is in a cold start state and step S2 is executed; otherwise, the engine is in a cold start state and the nozzle is heated at maximum power.

[0027] After engine startup, the nitrogen oxide (NOx) content in the exhaust gas is zero or low. As operating time increases, the engine temperature rises, combustion of the air-fuel mixture gradually improves, and the NOx content in the exhaust gas begins to increase. Simultaneously, the nozzles continue to heat at maximum power to further promote and improve combustion. When the engine temperature reaches a certain value, combustion further improves, but the exhaust temperature has not yet reached the ignition point of the selective catalytic reduction (SCR) device. At this point, the NOx content in the exhaust gas is higher than the preset value. The engine's operating state can be considered to be between a cold start state and a warm-up normal operating state. Therefore, the nozzle heating power can be adjusted according to the rate of change in exhaust NOx content. By monitoring the NOx content, the current state of the engine can be quickly determined, and it can be used to determine whether the conditions for adjusting the nozzle heating power are met, thus reducing the engine's operating time in the cold start state. The preset value for NOx content is determined based on actual engineering requirements and is not specifically limited here.

[0028] Furthermore, such as Figure 3 As shown, when the nitrogen oxide content is greater than the preset value, the engine's operating state is between the low-temperature cold start state and the warm-up normal operation state. The exhaust temperature has not yet reached the ignition point of the selective catalytic reduction device. At this time, the heating power of the nozzle is adjusted by the rate of change of nitrogen oxides. Then, step S2 includes: Continuously monitor the rate of change in nitrogen oxides; Determine if the rate of change of nitrogen oxides is ≤0; If the rate of change of nitrogen oxides is ≤0, then continue to determine whether the rate of change of nitrogen oxides remains ≤0 within a preset time; otherwise, the nozzle heats at maximum power. If the rate of change of nitrogen oxides remains ≤0 within a preset time, the heating power of the nozzle is reduced and step S3 is executed; otherwise, the nozzle is heated at maximum power.

[0029] Specifically, the change in nitrogen oxides (NOx) per unit time is continuously measured, i.e., the rate of change of NOx is continuously measured. If NOx shows an upward trend per unit time, the rate of change of NOx is >0; if NOx remains flat or shows a downward trend per unit time, the rate of change of NOx is ≤0. When the rate of change of NOx is >0, it indicates that the selective catalytic reduction device has not yet ignited or the catalytic reduction efficiency has not yet reached the normal level. At this time, the engine body temperature and the combustion effect of the air-fuel mixture have not reached the level required for normal operation. The nozzle maintains maximum power heating to continuously promote the improvement of the air-fuel mixture combustion effect. When the rate of change of NOx is ≤0, it indicates that the catalytic reduction efficiency of the selective catalytic reduction device has begun to increase. At this time, the engine body temperature and the combustion effect of the air-fuel mixture have reached a relatively ideal level required for normal operation. At this time, it is further determined whether the rate of change of NOx ≤0 can be maintained for a preset time. If it cannot be maintained for the preset time, it indicates that the current combustion state is unstable and the engine is still in a cold state. The nozzle continues to heat at maximum power. If it can be maintained for the preset time, it indicates that the current combustion is relatively stable and the engine is basically in a warm-up combustion state. At this time, it is necessary to reduce the heating power of the nozzle and focus on controlling engine knock. The preset time in this embodiment is determined based on actual engineering needs or calibration results, and is not specifically limited here. It should be noted that when the engine is in a warm-up state and has been running continuously for a period of time, the engine body temperature and combustion efficiency reach their optimal levels. At this time, the nitrogen oxide content in the exhaust gas will continue to rise. Therefore, continuing to judge whether the nitrogen oxide change rate ≤ 0 can be maintained for a preset time after the nitrogen oxide change rate ≤ 0 has two main functions: first, to avoid system misjudgment caused by short-term fluctuations, which would lead to knock control being performed when the engine is still in a cold state, resulting in a longer cold-state operation time; second, to avoid system misjudgment caused by the continued rise in nitrogen oxide content after the engine enters the warm-up state, thereby enabling timely knock control.

[0030] Furthermore, such as Figure 4 As shown, after the rate of change of nitrogen oxides is ≤0, it is further determined whether the rate of change of nitrogen oxides can be ≤0 for a preset time. At this time, the engine is basically in a warm-up state, and it is necessary to focus on controlling knocking. Step S3 includes: Continuously monitor whether the knock sensor emits a knock signal; If the knock sensor emits a knock signal, reduce the nozzle heating power; otherwise, maintain the current nozzle heating power and proceed to step S4.

[0031] Specifically, if the knock sensor emits a knock signal, it indicates abnormal combustion in the air-fuel mixture, and the nozzle heating power needs to be reduced until the knock signal from the knock sensor disappears. If the knock sensor does not emit a knock signal, the current nozzle heating power is maintained. The knock sensor is an acceleration sensor on the engine, and the knock signal is an abnormal acceleration signal from the acceleration sensor. Acceleration sensors and related methods for identifying knock through abnormal acceleration signals from acceleration sensors are existing technology in this field and will not be described in detail here.

[0032] Furthermore, such as Figure 5 As shown, when the knock sensor does not emit a knock signal, the engine operates smoothly. When the load changes, the engine operating conditions change, and the combustion state changes. The heating power of the nozzle needs to be adjusted synchronously. Step S4 includes: Obtain the actual heating temperature T of the nozzle, and obtain the required heating temperature T0; If T=T0, then the nozzle heating power remains unchanged; If T > T0, then reduce the nozzle heating power; If T < T0, increase the nozzle heating power and return to step S3.

[0033] Specifically, the actual heating temperature T of the nozzle is obtained, which is the heating temperature of the heating element on the nozzle. The required heating temperature T0 is obtained, which can be correlated with the engine load speed through calibration or MAP and stored in the engine control unit, and retrieved according to the actual engine load speed. If the actual heating temperature T = the required heating temperature T0, the nozzle heating power remains unchanged; if the actual heating temperature T > the required heating temperature T0, the actual heating temperature is too high, with a higher risk of knocking, and the nozzle heating power is reduced; if the actual heating temperature T < the required heating temperature T0, the actual heating temperature is too low, and the nozzle heating power is increased. Simultaneously, due to the increased nozzle heating power, knock control needs to continue to prevent knocking caused by the increased nozzle heating power. This setting allows for more precise control of the nozzle heating power while avoiding knocking, further optimizing the combustion effect of the air-fuel mixture in various speed ranges.

[0034] Furthermore, since the process of heat conduction from the heating element to the gas mixture and heating the mixture requires a certain amount of time, meaning that the increase or decrease in the heating power of the heating element is reflected in the increase or decrease in the temperature of the gas mixture with a certain delay, the required heating temperature T0 in this embodiment is taken from the required heating temperature range (T... 0i ,T 0a ), T 0i T is the lower limit of the required heating temperature range. 0aThis refers to the upper limit of the required heating temperature range, meaning that each engine's load speed is associated with a required heating temperature range, which can also be obtained through calibration or other methods. Therefore, step S4 specifically involves: Obtain the actual heating temperature T of the nozzle, and obtain the required heating temperature range (T). 0i ,T 0a ); If the actual heating temperature T falls within the required heating temperature range (T) 0i ,T 0a Within this range, the nozzle heating power remains unchanged; If the actual heating temperature T ≥ the upper limit of the required heating temperature range T 0a If so, the nozzle heating power will decrease; If the actual heating temperature T ≤ the lower limit of the required heating temperature range T 0i If so, increase the nozzle heating power while continuing knock control.

[0035] Set the required heating temperature T0 to be taken from the required heating temperature range (T 0i ,T 0a This effectively eliminates the time delay in the heat transfer from the heating element to the air-fuel mixture and its heating effect, thereby preventing knocking and further enabling precise control of the nozzle's heating power.

[0036] Optionally, the method further includes the following steps before step S1: The nozzle is heated at maximum power for a preheating time before fuel is injected.

[0037] Before a cold start at low temperatures, the nozzle is heated at maximum power for a preheating period. After the nozzle is preheated, fuel is injected. The nozzle can effectively heat the air-fuel mixture at the moment of a cold start, making the start-up process smoother.

[0038] Optionally, when the engine coolant temperature is ≥60°C, the nozzle does not need to continue heating the air-fuel mixture, and heating can be stopped at this time.

[0039] Specifically, the heating control method for the methanol heating nozzle in this embodiment can also be applied to the heating control of the methanol heating nozzle during engine hot start. During hot start, the engine block and exhaust system have a certain residual temperature. At this time, the nitrogen oxide content in the exhaust gas exceeds a preset value, and the selective catalytic reduction device ignites. The rate of change of nitrogen oxide content remains ≤0 within a preset time, allowing for rapid knock control during the cold start control phase and adjustment of the nozzle heating power according to the actual nozzle heating temperature.

[0040] like Figures 6-7As shown, this embodiment of the invention provides a methanol heating nozzle for executing the heating control method of the methanol heating nozzle in this embodiment. The methanol heating nozzle includes a valve body 1, a valve needle, and a heating assembly. The valve needle is slidably disposed within the valve body 1 to open or close the fuel passage. The heating assembly is sleeved inside the valve body 1 and can heat the valve body 1. By adjusting the current or duty cycle of the heating assembly, the power of the heating assembly is changed. During heating, the heating assembly heats the valve body 1, and the heated valve body 1 heats the methanol inside.

[0041] Specifically, the heating assembly includes a cylinder 3 and a heating element 4. One end of the cylinder 3 has a receiving groove that extends axially along the cylinder 3. The receiving groove is continuous circumferentially along the cylinder 3, forming an annular groove. The heating element 4 is disposed within the receiving groove. The inner wall of the cylinder 3 is fitted against the outer wall of the valve body 1 at the end where the nozzle is located, thereby heating the methanol at the nozzle. A thermally conductive agent is also coated between the cylinder 3 and the valve body 1 to fill the gap between them and improve heat transfer efficiency. The heating assembly and the valve body 1 are connected by a threaded sleeve 2. The threaded sleeve 2 is threadedly connected to the valve body 1, and a stop structure restricts the axial position of the threaded sleeve 2 on the valve body 1. The threaded sleeve 2 and the cylinder 3 are connected by a retaining spring 5, thereby achieving a fixed connection between the cylinder 3, the valve body 1, and the threaded sleeve 2. In other embodiments, the cylinder 3 and the threaded sleeve 2 can also be fixedly connected by welding or interference fit.

[0042] This invention provides a methanol engine that utilizes a methanol heating nozzle heating control method or includes the methanol heating nozzle described in this embodiment. By applying the methanol heating nozzle heating control method or including the methanol heating nozzle described in this embodiment, the low-temperature cold start performance of the methanol engine is improved, while simultaneously suppressing knocking tendency and reducing knocking duration to a certain extent.

[0043] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of disclosure in this invention is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-disclosed concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this invention.

[0044] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A heating control method for a methanol heating nozzle, characterized in that, include: S1. Obtain the nitrogen oxide content in the exhaust gas, and determine the engine status as cold start, cold engine, or warm-up based on the nitrogen oxide content. If the engine status is cold engine, proceed to step S2. S2. The methanol heating nozzle heats at maximum power and continuously obtains the change rate of nitrogen oxides in the exhaust gas until the change rate of nitrogen oxide content is ≤0 for a preset time, and then proceeds to step S3. S3. Obtain the knock signal from the knock sensor, adjust the heating power of the nozzle according to the knock signal, and execute step S4. S4. Adjust the nozzle heating power according to the actual heating temperature of the nozzle.

2. The heating control method for the methanol heating nozzle according to claim 1, characterized in that, Step S1 includes: Continuously obtain the content of nitrogen oxides; If the nitrogen oxide content is greater than the preset value, the engine is in a cold state and step S2 is executed; otherwise, the engine is in a cold start state and the nozzle is heated at maximum power.

3. The heating control method for the methanol heating nozzle according to claim 1, characterized in that, Step S2 includes: Continuously monitor the rate of change in nitrogen oxides; Determine if the rate of change of nitrogen oxides is ≤0; If the rate of change of nitrogen oxides is ≤0, then continue to determine whether the rate of change of nitrogen oxides remains ≤0 within a preset time; otherwise, the nozzle heats at maximum power. If the rate of change of nitrogen oxides remains ≤0 within a preset time, the heating power of the nozzle is reduced and step S3 is executed; otherwise, the nozzle is heated at maximum power.

4. The heating control method for the methanol heating nozzle according to claim 1, characterized in that, Step S3 includes: Continuously monitor whether the knock sensor emits a knock signal; If the knock sensor emits a knock signal, reduce the nozzle heating power; otherwise, maintain the current nozzle heating power and proceed to step S4.

5. The heating control method for the methanol heating nozzle according to claim 1, characterized in that, Step S4 includes: Obtain the actual heating temperature T of the nozzle, and obtain the required heating temperature T0; If T=T0, then the nozzle heating power remains unchanged; If T > T0, then reduce the nozzle heating power; If T < T0, increase the nozzle heating power and return to step S3.

6. The heating control method for the methanol heating nozzle according to claim 5, characterized in that, The required heating temperature T0 is taken from the required heating temperature range (T 0i ,T 0a ).

7. The heating control method for the methanol heating nozzle according to any one of claims 1-6, characterized in that, The procedure before step S1 also includes: The nozzle is heated at maximum power for a preheating time before fuel is injected.

8. A methanol heating nozzle, characterized in that, A heating control method for performing the methanol heating nozzle according to any one of claims 1-7, wherein the methanol heating nozzle comprises: Valve body (1) and valve needle, the valve needle being slidably disposed within the valve body (1) to open or close the fuel passage; A heating component is sleeved outside the valve body (1) and is capable of heating the valve body (1).

9. The methanol heating nozzle according to claim 8, characterized in that, The heating assembly includes a cylinder (3) and a heating element (4). One end of the cylinder (3) is provided with a receiving groove, which is continuous along the circumference of the cylinder (3). The heating element (4) is disposed in the receiving groove. The inner wall of the cylinder (3) is in contact with the outer wall of the valve body (1) at the end where the nozzle is disposed.

10. A methanol engine, characterized in that, The heating control method of the methanol heating nozzle according to any one of claims 1-7 or including the methanol heating nozzle according to any one of claims 8-9.

Images