Device for improving acceleration response of hydrogen engine and control method thereof

Abstract

The invention discloses a control method of a device for improving the acceleration response of a hydrogen engine, and the control method comprises the steps: firstly, testing the boost pressure of all working conditions on a test bed during the stable operation of the engine at a development stage, and building a target boost pressure model based on the rotating speed and load rate of the engine; the actual supercharging pressure of the turbocharger is measured in real time through a pressure sensor arranged on the intake manifold; when the opening degree of the accelerator is larger than a set value, it is indicated that the driver steps on the accelerator vigorously and needs to increase injected hydrogen combustion immediately to output large power, and at the moment, the engine enters a power mode; in the power mode, the air management system supplements compressed air into an air inlet pipe of the engine according to a proportional-integral-differential method; according to the proportional method, the supplement amount of the compressed air is adjusted in real time according to the current pressure deviation. The acceleration response of the hydrogen engine can be improved by newly adding a power mode based on the accelerator opening degree and the supercharging pressure deviation percentage.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of engine design and manufacturing, in particular to a device for improving the acceleration response of a hydrogen engine and a control method thereof. BACKGROUND

[0002] Traditional internal combustion engines are being transformed into low-carbon or zero-carbon fuel engines. Among the various fuel engine technology routes, hydrogen engines have become the most promising power system due to their near-zero carbon emission characteristics. In the past two years, engine manufacturers have focused their resources on developing hydrogen engines, and hydrogen engine technology has made rapid progress.

[0003] Although hydrogen engines emit less pollutants than diesel and gasoline engines, due to the low mass energy density of hydrogen and the response lag of the intake system, the acceleration response of hydrogen engines is much worse than that of traditional fuel engines, which seriously affects the market application of hydrogen engines. Matching a turbocharger can improve the maximum torque output of a hydrogen engine, but due to the inherent turbo lag effect, it cannot improve the acceleration response of a hydrogen engine. There is currently no very effective solution to the slow power response of hydrogen engines after the accelerator is pressed.

[0004] Based on the above reasons, how to solve and improve the acceleration response of hydrogen engines has become one of the problems to be solved in the industry.

[0005] The information disclosed in this BACKGROUND section is only for the purpose of increasing the understanding of the background of the present application and should not be regarded as an acknowledgment or any form of suggestion that this information forms prior art that is publicly known. SUMMARY

[0006] The purpose of the present application is to provide a device for improving the acceleration response of a hydrogen engine, which can improve the acceleration response of a hydrogen engine by adding a power mode based on the throttle opening degree and the boost pressure deviation percentage.

[0007] Another purpose of the present application is to provide a control method for the device for improving the acceleration response of a hydrogen engine.

[0008] To achieve the above purpose, the present application provides a device for improving the acceleration response of a hydrogen engine, comprising an air compressor, a filter, a gas tank, a pressure stabilizing valve and an air management system; the air compressor is arranged on the engine and is powered by the engine; the filter is arranged at the air outlet end of the air compressor; the gas tank is in communication with the air outlet end of the filter; the pressure stabilizing valve is arranged at the gas tank, which can control the air inlet and air outlet of the gas tank and ensure that the compressed air of a fixed pressure is output to the air inlet of the engine; the air management system is connected to the air compressor, the gas tank and the pressure stabilizing valve.

[0009] In a preferred embodiment, the device for improving the acceleration response of a hydrogen engine further comprises a pressure sensor and a temperature sensor; the pressure sensor is arranged at the intake manifold of the engine and can measure the actual boost pressure of the turbocharger in real time; the temperature sensor is arranged at the intake manifold of the engine and can measure the intake temperature in the intake manifold in real time; wherein the pressure sensor and the temperature sensor are connected to the air management system through the vehicle ECU.

[0010] To achieve the above-mentioned another object, the application further provides a control method of the device for improving the acceleration response of a hydrogen engine, which is applied to the control of the device as described above, and the control method comprises the following steps: firstly, in the development stage, testing the boost pressure of the engine under all working conditions when the engine is stably running on a test bench, and establishing a target boost pressure model based on the engine speed and the load rate; measuring the actual boost pressure of the turbocharger in real time by the pressure sensor arranged at the intake manifold; when the throttle opening is greater than a set value, it indicates that the driver is stepping on the accelerator hard and needs to increase the hydrogen injection to output more power, at this time the engine enters a power mode; and in the power mode, the air management system supplements compressed air into the intake pipe of the engine according to the proportional-integral-differential method; wherein the proportional method is to adjust the supplement amount of compressed air in real time according to the current pressure deviation.

[0011] In a preferred embodiment, the control method of the device for improving the acceleration response of a hydrogen engine further comprises that when the pressure deviation percentage is greater than a set value, it indicates that the intake amount is far below the target value, and the hydrogen cannot be fully combusted, at this time the engine enters the power mode.

[0012] In a preferred embodiment, the pressure deviation percentage = (target boost pressure - actual boost pressure) / target boost pressure × 100.

[0013] In a preferred embodiment, the integral method is to continuously correct the small residual deviation according to the historical cumulative pressure deviation.

[0014] In a preferred embodiment, the differential method is to correct the supplement amount of compressed air according to the change rate of the deviation.

[0015] In a preferred embodiment, the control method of the device for improving the acceleration response of a hydrogen engine further comprises:

[0016] The intake density = boost pressure / (air gas constant × intake temperature);

[0017] The intake flow = engine displacement × volumetric efficiency × engine speed × intake density / 120; and

[0018] The air-fuel ratio = intake flow / hydrogen injection amount.

[0019] In a preferred embodiment, the boost pressure and intake temperature can be obtained from pressure sensors and temperature sensors arranged at the intake manifold, and the volumetric efficiency can be preset during engine development.

[0020] In a preferred embodiment, the target values of air-fuel ratio under different conditions of the engine in the power mode are preset during engine development, and when the engine enters the power mode, the intake flow of air is greatly increased, and the hydrogen injection amount is also rapidly increased in proportion to the intake flow of air, so that a large amount of hydrogen is fully combusted in the cylinder to rapidly output power, thereby greatly improving the acceleration response of the hydrogen engine.

[0021] Compared with the prior art, the device for improving the acceleration response of the hydrogen engine and the control method thereof have the following beneficial effects: 1. The compressed air output by the air compressor is filtered to remove impurities and stored in the gas storage tank, and the intake and exhaust of the gas storage tank are controlled by the pressure stabilizing valve to supplement the intake pipe as needed. 2. A power mode based on the throttle opening and the boost pressure deviation percentage is added to improve the acceleration response of the hydrogen engine. 3. The air management system supplements the compressed air into the engine intake pipe according to the proportional-integral-derivative method to rapidly increase the intake amount during engine acceleration. 4. Through the speed density method and air-fuel ratio conversion, the hydrogen injection amount during acceleration is greatly increased and stable complete combustion in the cylinder is ensured to rapidly output power. In this way, the problem of slow power response after stepping on the accelerator of the current hydrogen engine is well solved. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a schematic diagram of the component configuration of the device according to an embodiment of the application;

[0023] Figure 2 is a control logic schematic diagram of the control method according to an embodiment of the application.

[0024] MAIN REFERENCE NUMERALS EXPLANATION:

[0025] η - pressure deviation percentage, θ - throttle opening, ρ - intake density, P - boost pressure, R - air gas constant, T - intake temperature, m - intake flow, V - engine displacement, ε - volumetric efficiency, n - engine speed, β - air-fuel ratio, N - hydrogen injection amount. DETAILED DESCRIPTION

[0026] The specific embodiments of the application will be described in detail below with reference to the accompanying drawings, but it should be understood that the protection scope of the application is not limited by the specific embodiments.

[0027] Unless otherwise clearly indicated, throughout the description and the claims, the term "comprise" or variations such as "comprises" or "comprising" will be understood to imply the inclusion of a stated element or group of elements but not the exclusion of any other element or group of elements.

[0028] As shown in Figure 1 A device for improving the acceleration response of a hydrogen engine according to a preferred embodiment of the present application comprises an air compressor, a filter, an air tank, a pressure stabilizing valve (not shown) and an air management system. The air compressor is arranged on the engine and is powered by the engine. The filter is arranged at the air outlet of the air compressor. The air inlet of the air tank is in communication with the air outlet of the filter. The pressure stabilizing valve is arranged at the air tank and is capable of controlling the air inlet and air outlet of the air tank and ensuring that compressed air at a fixed pressure is output to the air inlet of the engine. The air management system is in typical data connection with the air compressor, the air tank and the pressure stabilizing valve.

[0029] In some embodiments, the device for improving the acceleration response of a hydrogen engine further comprises a pressure sensor (not shown) and a temperature sensor (not shown). The pressure sensor is arranged at the air inlet manifold of the engine and is capable of measuring the actual boost pressure P of the turbocharger in real time. The temperature sensor is arranged at the air inlet manifold of the engine and is capable of measuring the air temperature T in the air inlet manifold in real time. The pressure sensor and the temperature sensor are in typical data connection with the air management system through the vehicle ECU (not shown).

[0030] As shown in Figure 2 A control method for a device for improving the acceleration response of a hydrogen engine according to a preferred embodiment of the present application is applied to the control of the device as described above. The control method comprises the following steps. First, in the development stage, the boost pressure P of the engine under all working conditions when the engine is stably running is tested on a test bench. A target boost pressure P model is established based on the engine speed n and the load rate. The actual boost pressure P of the turbocharger is measured in real time by a pressure sensor arranged at the air inlet manifold. When the throttle opening is greater than a set value, it indicates that the driver is stepping on the accelerator hard and needs to increase the hydrogen injection output immediately to generate greater power. At this time, the engine enters a power mode. In the power mode, the air management system supplements compressed air into the air inlet pipe of the engine according to a proportional-integral-derivative method. The proportional method is to adjust the amount of compressed air supplement in real time according to the current pressure deviation. This correction method can quickly increase the boost pressure P and reduce the steady-state deviation, but there is a risk of pressure overshoot.

[0031] As shown in Figure 1 In some embodiments, the air compressor provided by the engine supplies compressed air. A filter is installed to clean the impurities in the compressed air. The clean compressed air is stored in an air tank. A pressure stabilizing valve is used to control the air inlet and air outlet of the air tank to ensure that compressed air at a fixed pressure is output.

[0032] In some embodiments, the control method of the device for improving the acceleration response of a hydrogen engine further comprises that when the pressure deviation percentage η is greater than a set value, it indicates that the intake air amount is far below the target value, and the hydrogen cannot be sufficiently combusted, at which time the engine enters the power mode.

[0033] In some embodiments, the pressure deviation percentage η = (target supercharging pressure - actual supercharging pressure) / target supercharging pressure x 100.

[0034] In some embodiments, the integral method is to continuously correct the small residual deviation according to the historical cumulative pressure deviation amount. This correction method slightly increases the supercharging pressure P and completely eliminates the steady-state error, but the response is slow, and overuse can cause overshoot.

[0035] In some embodiments, the differential method is to correct the amount of compressed air supplement according to the rate of change of the deviation. This correction is proportional to the rate of change of the deviation, which suppresses system fluctuations in advance and can reduce the overshoot amount and improve stability.

[0036] In some embodiments, the control method of the device for improving the acceleration response of a hydrogen engine further comprises:

[0037] The intake air density ρ = supercharging pressure P / (air gas constant R x intake air temperature T);

[0038] The intake air flow rate m = engine displacement V x volumetric efficiency ε x engine speed n x intake air density ρ / 120; and

[0039] The air-fuel ratio β = intake air flow rate m / hydrogen injection amount N.

[0040] In some embodiments, the supercharging pressure P and the intake air temperature T can be obtained from the pressure sensor and the temperature sensor arranged at the intake manifold, and the volumetric efficiency ε can be preset during engine development.

[0041] In some embodiments, during engine development, the target value of the air-fuel ratio β under different conditions of the engine in the power mode is preset. When the engine enters the power mode, the intake air flow rate m of the air is greatly increased, and the hydrogen injection amount N can also be rapidly increased in proportion to the intake air flow rate m of the air, a large amount of hydrogen is sufficiently combusted in the cylinder, and power is rapidly output, which can greatly improve the acceleration response of the hydrogen engine.

[0042] In summary, the device for improving the acceleration response of a hydrogen engine and the control method thereof have the following advantages: first, the compressed air output by the air compressor is filtered to remove impurities and stored in the air tank, and the air inlet and air outlet of the air tank are controlled by the pressure stabilizing valve, and the compressed air is supplemented to the air inlet pipe according to the demand; second, a power mode based on the throttle opening degree and the deviation percentage of the boost pressure is added to improve the acceleration response of the hydrogen engine; third, the air management system supplements the compressed air to the engine air inlet pipe according to the proportional-integral-derivative method, and quickly increases the air intake amount during the engine acceleration process; fourth, through the speed density method and air-fuel ratio conversion, the hydrogen injection amount during the acceleration process is greatly increased and stable and complete combustion in the cylinder is ensured, and power is quickly output. In this way, the problem of slow power response after stepping on the accelerator of the current hydrogen engine is well solved.

[0043] The foregoing description of specific exemplary embodiments of the application is intended to be illustrative only and is not intended to limit the application to the precise forms described. Many modifications and variations are possible in light of the above teachings without departing from the spirit or essential characteristics of the present application. The exemplary embodiments were chosen and described in order to explain the principles of the application and its practical application and to allow others skilled in the art to understand the application for various exemplary embodiments and its various modifications as are suited to the particular use contemplated. It is intended that the scope of the application be defined by the claims and their equivalents.

Claims

1. A device for improving the acceleration response of a hydrogen engine, characterized in that, include: An air compressor, which is mounted on an engine and powered by the engine; A filter is installed at the air outlet of the air compressor; An air storage tank, the air inlet of which is connected to the air outlet of the filter; A pressure regulating valve is installed at the air tank. The pressure regulating valve can control the air intake and exhaust of the air tank and ensure that compressed air at a fixed pressure is output to the air intake of the engine. as well as An air management system is typically connected via data links to the air compressor, the air tank, and the pressure regulating valve.

2. The apparatus for improving the acceleration response of a hydrogen engine as described in claim 1, characterized in that, Also includes: A pressure sensor is installed at the intake manifold of the engine and can measure the actual boost pressure of the turbocharger in real time. as well as A temperature sensor is installed in the intake manifold of the engine and can measure the intake air temperature in the intake manifold in real time. The pressure sensor and the temperature sensor are typically connected to the air management system via the vehicle ECU.

3. A control method for an apparatus for improving the acceleration response of a hydrogen engine, applied to the control of the apparatus as described in any one of claims 1 to 2, characterized in that, The control method includes: First, during the development phase, the boost pressure of the engine under all operating conditions during stable operation is tested on a test bench. Based on the engine's speed and load rate, a target boost pressure model is established. The actual boost pressure of the turbocharger is measured in real time by the pressure sensor arranged in the intake manifold; When the throttle opening is greater than the set value, it means that the driver is pressing the accelerator hard and needs to immediately increase the injection of hydrogen to burn and output greater power. At this time, the engine will enter the power mode. In the power mode, the air management system supplies compressed air to the engine's intake manifold using a proportional-integral-derivative method; The proportional method involves adjusting the amount of compressed air supplied in real time based on the current pressure deviation.

4. The control method of the device for improving the acceleration response of a hydrogen engine as described in claim 3, characterized in that, It also includes a situation where, when the pressure deviation percentage is greater than the set value, it indicates that the intake air volume is far below the target value and the hydrogen cannot be fully combusted. At this time, the engine will enter the power mode.

5. The control method of the apparatus for improving the acceleration response of a hydrogen engine as described in claim 4, characterized in that, Pressure deviation percentage = (target boost pressure - actual boost pressure) / target boost pressure × 100.

6. The control method of the apparatus for improving the acceleration response of a hydrogen engine as described in claim 3, characterized in that, The integration method continuously corrects for minute residual deviations based on historical cumulative pressure deviations.

7. The control method of the apparatus for improving the acceleration response of a hydrogen engine as described in claim 3, characterized in that, The differential method adjusts the amount of compressed air replenishment based on the rate of change of the deviation.

8. The control method of the apparatus for improving the acceleration response of a hydrogen engine as described in claim 3, characterized in that, Also includes: Intake density = boost pressure / (air gas constant × intake temperature); Intake flow rate = engine displacement × volumetric efficiency × engine speed × intake air density / 120; and Air-fuel ratio = intake air flow rate / hydrogen injection rate.

9. The control method of the apparatus for improving the acceleration response of a hydrogen engine as described in claim 8, characterized in that, The boost pressure and the intake air temperature can be obtained from the pressure sensor and the temperature sensor arranged in the intake manifold, and the volumetric efficiency can be preset during engine development.

10. The control method of the apparatus for improving the acceleration response of a hydrogen engine as described in claim 8, characterized in that, During the engine development, the target values ​​of the air-fuel ratio under different operating conditions of the engine in power mode are preset. When the engine enters power mode, the air intake flow rate increases significantly, and the hydrogen injection quantity can also increase rapidly in proportion to the air intake flow rate. A large amount of hydrogen is fully combusted in the cylinder, quickly doing work and outputting power, which can greatly improve the acceleration response of the hydrogen engine.

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