Methanol pump supply pressure follow-up strategy based on injection pulse width of methanol nozzle

Abstract

The invention discloses a methanol pump supply pressure follow-up strategy based on injection pulse width of a methanol nozzle, relates to an engine control technology, and solves the technical problem that combustion in a cylinder is influenced by inconsistent injection pulse width of an existing methanol engine under different loads. The strategy comprises the steps that the real-time load and the real-time injection pulse width of an engine are obtained, an injection pulse width set value is calibrated according to the real-time load, and when the real-time injection pulse width is larger than the injection pulse width set value, a first adjusting measure is triggered to control a methanol pump so that the real-time injection pulse width can be equal to the injection pulse width set value; and when the real-time injection pulse width is smaller than the injection pulse width set value, a second adjusting measure is triggered to control the methanol pump so that the real-time injection pulse width can be equal to the injection pulse width set value. According to the invention, under different loads of the methanol engine, the injection pulse width of the methanol nozzle is controlled at a proper value, and the combustion efficiency in a methanol engine cylinder is improved.

Description

Technical Field

[0001] The present invention relates to engine control technology, and more particularly to a methanol pump supply pressure following strategy based on methanol nozzle injection pulse width. Background Art

[0002] Existing spark-ignition methanol engines utilize multi-point injection technology through the intake manifold. This technology maintains a fixed methanol inlet pressure, and the amount of methanol injected can only be adjusted by adjusting the nozzle pulse width. This pulse width increases with increasing engine load. When a methanol engine is used for power generation, the intake time is fixed, and the engine typically operates at a constant speed. However, when the engine is subjected to varying loads, an injection pulse width that is too short or too long can affect the efficiency of methanol inlet and, consequently, combustion within the cylinder. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to address the deficiencies of the existing technology and provide a methanol pump supply pressure following strategy based on the methanol nozzle injection pulse width to solve the technical problem that the injection pulse width of the existing methanol engine is inconsistent under different loads and affects the combustion in the cylinder.

[0004] The present invention discloses a methanol pump supply pressure following strategy based on the injection pulse width of a methanol nozzle. The strategy comprises the following steps: obtaining the real-time load and the real-time injection pulse width of the engine, calibrating the injection pulse width setting value according to the real-time load, and triggering a first regulating measure to control the methanol pump so that the real-time injection pulse width is equal to the injection pulse width setting value when the real-time injection pulse width is greater than the injection pulse width setting value; and triggering a second regulating measure to control the methanol pump so that the real-time injection pulse width is equal to the injection pulse width setting value when the real-time injection pulse width is less than the injection pulse width setting value.

[0005] As a further improvement, the first adjustment measure is to obtain a first pulse width difference by subtracting the real-time injection pulse width from the injection pulse width set value, compare the first pulse width difference with a preset first pulse width difference threshold, and when the first pulse width difference is less than the first pulse width difference threshold, increase the speed of the methanol pump motor to a preset first speed to increase the supply pressure of the methanol pump;

[0006] When the first pulse width difference is greater than or equal to a first pulse width difference threshold, the rotational speed of the methanol pump motor is increased to a preset second rotational speed so that the first pulse width difference is less than the first pulse width difference threshold.

[0007] Furthermore, the first speed is less than the second speed.

[0008] Furthermore, the second adjustment measure is to obtain a second pulse width difference by subtracting the real-time injection pulse width from the injection pulse width set value, compare the second pulse width difference with a preset second pulse width difference threshold, and when the second pulse width difference is less than the second pulse width difference threshold, reduce the speed of the methanol pump motor to a preset third speed to reduce the supply pressure of the methanol pump;

[0009] When the second pulse width difference is greater than or equal to a second pulse width difference threshold, the rotational speed of the methanol pump motor is reduced to a preset fourth rotational speed so that the second pulse width difference is less than the second pulse width difference threshold.

[0010] Furthermore, the third speed>the fourth speed.

[0011] Furthermore, the greater the real-time load of the engine, the smaller the injection pulse width setting value is calibrated.

[0012] Beneficial effects

[0013] The advantages of the present invention are:

[0014] The present invention obtains the real-time load and real-time injection pulse width of the engine, calibrates the injection pulse width setting value according to the real-time load, and when the real-time injection pulse width is greater than the injection pulse width setting value, triggers a first adjustment measure to control the methanol pump so that the real-time injection pulse width is equal to the injection pulse width setting value; when the real-time injection pulse width is less than the injection pulse width setting value, triggers a second adjustment measure to control the methanol pump so that the real-time injection pulse width is equal to the injection pulse width setting value, thereby achieving the goal of controlling the methanol nozzle injection pulse width at a suitable value under different loads of the methanol engine, thereby improving the combustion efficiency in the cylinder of the methanol engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a calibration curve diagram of the real-time load and injection pulse width setting value of the present invention. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with the embodiments, but this does not constitute any limitation to the present invention. Any limited number of modifications made by anyone within the scope of the claims of the present invention are still within the scope of the claims of the present invention.

[0017] See Figure 1The present invention provides a methanol pump supply pressure following strategy based on the injection pulse width of the methanol nozzle. The strategy is to obtain the real-time load and real-time injection pulse width of the engine, calibrate the injection pulse width setting value according to the real-time load, and when the real-time injection pulse width is greater than the injection pulse width setting value, trigger the first adjustment measure to control the methanol pump so that the real-time injection pulse width is equal to the injection pulse width setting value; when the real-time injection pulse width is less than the injection pulse width setting value, trigger the second adjustment measure to control the methanol pump so that the real-time injection pulse width is equal to the injection pulse width setting value.

[0018] The first adjustment measure is to obtain a first pulse width difference by subtracting the real-time injection pulse width from the injection pulse width setting value, and compare the first pulse width difference with a preset first pulse width difference threshold. When the first pulse width difference is less than the first pulse width difference threshold, the speed of the methanol pump motor is increased to the preset first speed to increase the supply pressure of the methanol pump.

[0019] When the first pulse width difference is greater than or equal to the first pulse width difference threshold, the rotational speed of the methanol pump motor is increased to a preset second rotational speed so that the first pulse width difference is less than the first pulse width difference threshold.

[0020] The first speed is less than the second speed. When the first pulse width difference is greater than or equal to the first pulse width difference threshold, the methanol pump supply pressure is rapidly increased by the higher second speed, quickly reducing the first pulse width difference to less than the first pulse width difference threshold. When the first pulse width difference is less than the first pulse width difference threshold, the methanol pump supply pressure is slowly increased by the lower first speed, achieving interval-based regulation of the methanol pump supply pressure. This allows for more accurate control of the methanol pump supply pressure, improves combustion efficiency within the methanol engine cylinder, and increases methanol fuel utilization.

[0021] The second adjustment measure is to obtain a second pulse width difference by subtracting the real-time injection pulse width from the injection pulse width set value, and compare the second pulse width difference with a preset second pulse width difference threshold. When the second pulse width difference is less than the second pulse width difference threshold, the speed of the methanol pump motor is reduced to a preset third speed to reduce the supply pressure of the methanol pump.

[0022] When the second pulse width difference is greater than or equal to the second pulse width difference threshold, the rotational speed of the methanol pump motor is reduced to a preset fourth rotational speed so that the second pulse width difference is less than the second pulse width difference threshold.

[0023] The third speed is greater than the fourth speed. When the second pulse width difference is greater than or equal to the second pulse width difference threshold, the methanol pump supply pressure is rapidly reduced at the lower fourth speed, quickly reducing the second pulse width difference to less than the second pulse width difference threshold. When the second pulse width difference is less than the second pulse width difference threshold, the methanol pump supply pressure is slowly reduced at the higher third speed, bringing the real-time injection pulse width closer to the injection pulse width set value. This achieves interval-based regulation of the methanol pump supply pressure, more accurately controlling the methanol pump supply pressure, improving combustion efficiency within the methanol engine cylinder, and increasing the utilization rate of methanol fuel.

[0024] from Figure 1 The curve shows that the greater the real-time engine load, the smaller the calibrated injection pulse width setting value. Specifically, when the real-time engine load is 10kW, the calibrated injection pulse width setting value is 10ms; when the real-time engine load is 40kW, the calibrated injection pulse width setting value is 18ms.

[0025] The above is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the structure of the present invention. These modifications and improvements will not affect the effect of the implementation of the present invention and the practicality of the patent.

Claims

1. A methanol pump supply pressure following strategy based on methanol nozzle injection pulse width, characterized in that: The strategy is to obtain the real-time load and real-time injection pulse width of the engine, calibrate the injection pulse width setting value according to the real-time load, and when the real-time injection pulse width is greater than the injection pulse width setting value, trigger the first adjustment measure to control the methanol pump so that the real-time injection pulse width is equal to the injection pulse width setting value; when the real-time injection pulse width is less than the injection pulse width setting value, trigger the second adjustment measure to control the methanol pump so that the real-time injection pulse width is equal to the injection pulse width setting value.

2. The methanol pump supply pressure following strategy based on methanol nozzle injection pulse width according to claim 1, characterized in that: The first adjustment measure is to obtain a first pulse width difference by subtracting the real-time injection pulse width from the injection pulse width set value, compare the first pulse width difference with a preset first pulse width difference threshold, and when the first pulse width difference is less than the first pulse width difference threshold, increase the speed of the methanol pump motor to a preset first speed to increase the supply pressure of the methanol pump; When the first pulse width difference is greater than or equal to a first pulse width difference threshold, the rotational speed of the methanol pump motor is increased to a preset second rotational speed so that the first pulse width difference is less than the first pulse width difference threshold.

3. A methanol pump supply pressure following strategy based on methanol nozzle injection pulse width according to claim 2, characterized in that: The first speed is less than the second speed.

4. The methanol pump supply pressure following strategy based on methanol nozzle injection pulse width according to claim 1, characterized in that: The second adjustment measure is to obtain a second pulse width difference by subtracting the real-time injection pulse width from the injection pulse width set value, compare the second pulse width difference with a preset second pulse width difference threshold, and when the second pulse width difference is less than the second pulse width difference threshold, reduce the speed of the methanol pump motor to a preset third speed to reduce the supply pressure of the methanol pump; When the second pulse width difference is greater than or equal to a second pulse width difference threshold, the rotational speed of the methanol pump motor is reduced to a preset fourth rotational speed so that the second pulse width difference is less than the second pulse width difference threshold.

5. The methanol pump supply pressure following strategy based on methanol nozzle injection pulse width according to claim 4, characterized in that: The third speed>the fourth speed.

6. The methanol pump supply pressure following strategy based on methanol nozzle injection pulse width according to claim 1, characterized in that: The greater the real-time load of the engine, the smaller the injection pulse width setting value is calibrated.

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