Low-temperature starting device of methanol engine

Abstract

The invention discloses a low-temperature starting device of a methanol engine. The low-temperature starting device comprises a gasoline supply system and an ECU. The gasoline supply system is arranged at a cylinder cover of the engine and comprises a plurality of gasoline injectors, a gasoline rail pipe, a gasoline fine filter and a gasoline fine filter; the plurality of gasoline injectors are arranged at an air inlet channel of the cylinder cover; the gasoline rail pipe is used for providing gasoline fuel for the gasoline injectors; the gasoline fuel filtered by the gasoline fine filter enters a gasoline rail pipe; the gasoline tank provides gasoline fuel for the gasoline rail pipe through the gasoline fine filter; and the ECU controls the gasoline supply system to supply oil to the engine in advance when the engine is cold-started, so that the engine is normally started. Therefore, a gasoline supply and injection system is additionally arranged on the cylinder cover of the engine, gasoline is used for heating the engine during cold start, and a methanol system is switched to when the temperature of cooling water reaches 25 DEG C.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of engine design and manufacture, in particular to a low-temperature starting device for a methanol engine. BACKGROUND

[0002] I. Advantages of methanol fuel

[0003] 1. Methanol is a clean fuel.

[0004] 2. China is rich in coal, poor in oil and gas, and methanol is made from coal, so the source is relatively abundant. Developing methanol fuel can reduce the dependence on oil energy

[0005] II. Disadvantages of methanol fuel

[0006] Methanol has a large latent heat of evaporation, and the latent heat of evaporation of methanol is 1109 kJ / kg, which is 3.7 times the latent heat of evaporation of gasoline (310 kJ / kg) and 3.9 times the latent heat of evaporation of diesel (280 kJ / kg). Therefore, under low temperature conditions, due to the high latent heat of evaporation of methanol, the cold start performance of methanol gasoline is poor, and technical measures need to be taken to solve this problem

[0007] III. Existing methanol cold start solutions

[0008] 1. Electric heating of cooling water: a set of electric heating device is needed, which uses electric heating wire to heat the cooling water circulating in the engine. This scheme increases the cost and the space requirement for wire arrangement, and has electromagnetic interference, increasing the safety hazard.

[0009] 2. Electric heating plug heating: an electric heating plug is arranged beside the fuel injector, and after the electric heating plug is heated, methanol is sprayed on the electric heating plug to make the methanol gasify. This scheme increases the space requirement for wire arrangement. There is electromagnetic interference, increasing the safety hazard

[0010] 3. Methanol cracking: a cracking device, hydrogen (dimethyl ether) storage and injection system need to be added, which is high in cost and difficult to arrange.

[0011] The information disclosed in this BACKGROUND section is only intended to increase an understanding of the general context of the present application and is not to be taken in any way as an acknowledgment or any form of suggestion that this information forms prior art that is already known in the art. SUMMARY

[0012] The purpose of the present application is to provide a low-temperature starting device for a methanol engine, which adds a set of gasoline supply and injection system on the engine cylinder head. During cold start, gasoline is used to heat the engine, and when the cooling water temperature reaches 25°C, the methanol system is switched.

[0013] To achieve the above object, the application provides a low-temperature starting device for a methanol engine, which comprises a gasoline supply system and an ECU; the gasoline supply system is arranged at the cylinder head of the engine, and comprises a plurality of gasoline injectors, a gasoline rail, a gasoline filter and a gasoline filter; the plurality of gasoline injectors are arranged at the intake port of the cylinder head; the gasoline rail is used to supply gasoline fuel to the plurality of gasoline injectors; the gasoline fuel filtered by the gasoline filter enters the gasoline rail; the gasoline tank supplies the gasoline fuel to the gasoline rail through the gasoline filter; and the ECU controls the gasoline supply system to supply oil to the engine to start the engine normally when the engine is cold started.

[0014] In a preferred embodiment, the low-temperature starting device for the methanol engine further comprises a methanol supply system, which comprises a plurality of methanol injectors, a methanol rail, a methanol filter, a methanol tank and a methanol pump; the plurality of methanol injectors are arranged at the intake port of the cylinder head; the methanol rail is used to supply methanol fuel to the plurality of methanol injectors; the methanol fuel filtered by the methanol filter enters the methanol rail; the methanol tank supplies the methanol fuel to the methanol rail through the methanol filter; the inlet of the methanol pump is communicated with the methanol tank, and the outlet is communicated with the inlet of the methanol filter; and the ECU can control the injection amount and pressure of the methanol entering the intake port through the methanol pump and the plurality of methanol injectors.

[0015] In a preferred embodiment, the methanol supply system further comprises a methanol coarse filter and a pressure control valve; the methanol coarse filter is arranged in the methanol tank or upstream of the inlet of the methanol pump; the pressure control valve is arranged at the methanol pump, and the ECU can control the output pressure of the methanol pump through the pressure control valve.

[0016] In a preferred embodiment, the number of the gasoline rail and the methanol rail is two, each gasoline rail comprises a plurality of gasoline injectors, and each methanol rail comprises a plurality of methanol injectors.

[0017] In a preferred embodiment, the gasoline injectors and the methanol injectors spray gasoline or methanol according to the injection instruction pulse issued by the ECU, the injection start point is controlled by the start point of the instruction pulse, and the injection amount is controlled by the width of the instruction pulse.

[0018] In a preferred embodiment, the injection pressure of the gasoline injectors and the methanol injectors is common rail pressure, the pressure of the methanol rail is 5 bar, and the pressure of the gasoline rail is 4 bar.

[0019] In a preferred embodiment, the methanol supply system further comprises a first heater, a second heater and a third heater, which are arranged in series between the methanol pump and the methanol rail.

[0020] In a preferred embodiment, the methanol supply system further comprises a first temperature sensor, a second temperature sensor, a third temperature sensor and a fourth temperature sensor; the first temperature sensor is arranged at the outlet of the pressure control valve; the second temperature sensor is arranged at the outlet of the first heater; the third temperature sensor is arranged at the outlet of the second heater; and the fourth temperature sensor is arranged at the outlet of the third heater.

[0021] In a preferred embodiment, when the gasoline supply system has been running for a period of time and the cooling water of the engine reaches a certain temperature, the ECU sends a switching instruction, the gasoline supply system stops running, and the methanol supply system starts running.

[0022] In a preferred embodiment, when the temperature detected by the first temperature sensor is less than or equal to the working required temperature, the ECU sends an instruction to start heating the first heater; when the temperature detected by the second temperature sensor is less than or equal to the working required temperature, the ECU sends an instruction to start heating the second heater; when the temperature detected by the third temperature sensor is less than or equal to the working required temperature, the ECU sends an instruction to start heating the third heater; when the temperature detected by the fourth temperature sensor is greater than the working required temperature by a certain value, the ECU sends an instruction to stop heating the first heater; when the temperature detected by the fourth temperature sensor is still greater than the working required temperature by the certain value after the first heater has stopped heating for a period of time, the ECU sends an instruction to stop heating the second heater; and when the temperature detected by the fourth temperature sensor is still greater than the working required temperature by the certain value after the first heater and the second heater have both stopped heating for a period of time, the ECU sends an instruction to stop heating the third heater.

[0023] Compared with the prior art, the low-temperature starting device of the methanol engine has the following beneficial effects: the scheme overcomes the problem of difficult cold starting existing in the prior art by adding a set of gasoline supply system on the engine cylinder head, using gasoline to heat the engine during cold starting, and switching to the methanol supply system when the cooling water temperature reaches 25 DEG C. The methanol supply system draws methanol from a methanol tank through a methanol pump, pressurizes the methanol, and then sprays the methanol into an air intake duct through a methanol injector to fully mix the methanol with air, and when the intake valve above the cylinder is opened, the mixture enters the combustion chamber and is ignited by a spark plug. The gasoline auxiliary injection system is used for low-temperature starting conditions, and the injection principle is the same as that of the methanol injection system; after warming up, the methanol combustion is switched from the gasoline combustion. Meanwhile, the methanol supply system is also provided with a methanol coarse filter, a methanol pump, a methanol filter, a pressure control valve, a methanol rail pipe / rail pressure sensor / methanol injector (integrated on the methanol guide rail component), and a heater, and the ECU can control the start or stop of the heater according to the temperature information fed back by the temperature sensor. The scheme has the advantages of small influence on the engine body structure, no electromagnetic interference, small safety hazard, simple installation and easy operation by using the original cooling liquid pipeline and circulation control strategy of the engine, and remarkable heating effect. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a three-dimensional appearance schematic diagram of a low-temperature starting device according to an embodiment of the present application;

[0025] Figure 2 is a schematic diagram of the internal cross-sectional structure of a low-temperature starting device according to an embodiment of the present application;

[0026] Figure 3 is a schematic diagram of the configuration of system components of a low-temperature starting device according to an embodiment of the present application;

[0027] Figure 4 is a schematic diagram of the control circuit of a low-temperature starting device according to an embodiment of the present application;

[0028] Figure 5 is a schematic diagram of the structure of a double rail pipe of a low-temperature starting device according to an embodiment of the present application;

[0029] Figure 6 is a schematic diagram of the structure of a heating device of a low-temperature starting device according to an embodiment of the present application. DETAILED DESCRIPTION

[0030] The specific embodiments of the present application are described in detail below with reference to the accompanying drawings, but it should be understood that the protection scope of the present application is not limited by the specific embodiments.

[0031] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.

[0032] like Figures 1 to 6 As shown, a cold-start device for a methanol engine according to a preferred embodiment of the present invention includes a gasoline supply system and an ECU. The gasoline supply system is located at the cylinder head of the engine and includes multiple gasoline injectors, a gasoline rail, a gasoline filter, and a gasoline fine filter. The multiple gasoline injectors are located at the intake manifold of the cylinder head. The gasoline rail is used to supply gasoline fuel to the multiple gasoline injectors. The gasoline fuel filtered by the gasoline fine filter enters the gasoline rail. The gasoline tank supplies gasoline fuel to the gasoline rail through the gasoline fine filter. Generally, a gasoline pump (not shown) is integrated in the gasoline tank. The gasoline pump is typically connected to the ECU. The gasoline injectors are supplied with injection pressure by the gasoline pump and controlled by the ECU. The ECU controls the gasoline supply system to supply fuel to the engine first during a cold start to enable the engine to start normally.

[0033] In some embodiments, the low-temperature starting device for the methanol engine also includes a methanol supply system, which includes multiple methanol injectors, a methanol rail, a methanol filter, a methanol tank, and a methanol pump; the multiple methanol injectors are located at the intake manifold of the cylinder head; the methanol rail is used to supply methanol fuel to the multiple methanol injectors; the methanol fuel filtered by the methanol filter enters the methanol rail; the methanol tank supplies methanol fuel to the methanol rail through the methanol filter; the inlet of the methanol pump is connected to the methanol tank, and the outlet is connected to the inlet of the methanol filter; the ECU can control the injection quantity and pressure of methanol entering the intake manifold through the methanol pump and the multiple methanol injectors.

[0034] In some implementations, the methanol supply system further includes a methanol coarse filter and a pressure control valve; the methanol coarse filter is located inside the methanol tank or upstream of the methanol pump inlet; the pressure control valve is located at the methanol pump, and the ECU can control the output pressure of the methanol pump through the pressure control valve.

[0035] In some implementations, there are two gasoline rails and two methanol rails, each gasoline rail including multiple gasoline injectors and each methanol rail including multiple methanol injectors.

[0036] In some implementations, the gasoline injector and the methanol injector inject gasoline or methanol according to the injection command pulse issued by the ECU. The injection start point is controlled by the start point of the command pulse, and the injection quantity is controlled by the width of the command pulse.

[0037] In some embodiments, the injection pressure of the gasoline injector and the methanol injector is the common rail pressure, the methanol rail pressure is 5 bar, and the gasoline rail pressure is 4 bar.

[0038] In some embodiments, the methanol supply system further comprises a first heater, a second heater, and a third heater, which are arranged in series between the methanol pump and the methanol rail.

[0039] In some embodiments, the methanol supply system further comprises a first temperature sensor, a second temperature sensor, a third temperature sensor, and a fourth temperature sensor; the first temperature sensor is arranged at the outlet of the pressure control valve; the second temperature sensor is arranged at the outlet of the first heater; the third temperature sensor is arranged at the outlet of the second heater; and the fourth temperature sensor is arranged at the outlet of the third heater.

[0040] In some embodiments, the heater can also be a separate heater with several heating functions, so that the temperature controller can monitor the temperature data before and after the heater at any time and feed back to the ECU in real time.

[0041] In some embodiments, when the gasoline supply system has been running for a period of time and the cooling water of the engine reaches a certain temperature, the ECU sends a switching instruction, and the gasoline supply system stops running while the methanol supply system starts running.

[0042] In some embodiments, when the temperature detected by the first temperature sensor is less than or equal to the working required temperature, the ECU sends an instruction to start heating the first heater; when the temperature detected by the second temperature sensor is less than or equal to the working required temperature, the ECU sends an instruction to start heating the second heater; when the temperature detected by the third temperature sensor is less than or equal to the working required temperature, the ECU sends an instruction to start heating the third heater; when the temperature detected by the fourth temperature sensor is greater than the working required temperature by a certain value, the ECU sends an instruction to stop heating the first heater; when the temperature detected by the fourth temperature sensor is still greater than the working required temperature by a certain value after the first heater has stopped heating for a period of time, the ECU sends an instruction to stop heating the second heater; and when the temperature detected by the fourth temperature sensor is still greater than the working required temperature by a certain value after the first heater and the second heater have both stopped heating for a period of time, the ECU sends an instruction to stop heating the third heater.

[0043] In some embodiments, in summary, the purpose of heating the methanol fuel by the heater is to keep the methanol fuel within a reasonable working temperature range, and if the temperature detected by the fourth temperature sensor is higher than the reasonable working temperature range, the heating intensity of the heater is reduced, and vice versa.

[0044] In summary, the low-temperature starting device of the methanol engine has the following advantages: the scheme adds a set of gasoline supply system on the engine cylinder head, uses gasoline to heat the engine during cold start, overcomes the problem of cold start difficulty existing in the prior art, and switches to the methanol supply system when the cooling water temperature reaches 25°C. The methanol supply system draws methanol from the methanol tank through the methanol pump, pressurizes, and then sprays it into the intake port through the methanol injector, mixes with air, and when the intake valve above the cylinder is opened, the mixture enters the combustion chamber and is ignited by the spark plug. The gasoline auxiliary injection system is used for low-temperature starting conditions, and the injection principle is the same as that of the methanol injection system; after warming up, it will switch from gasoline combustion to methanol combustion. At the same time, the methanol supply system is also equipped with a methanol coarse filter, a methanol pump, a methanol filter, a pressure control valve, a methanol rail pipe / rail pressure sensor / methanol injector (integrated on the methanol guide rail component), and a heater. The ECU can control the start or stop of the heater through the temperature information fed back by the temperature sensor. The scheme has the advantages of less influence on the engine body structure, no electromagnetic interference, small safety hazard, simple installation and easy operation by using the original cooling liquid pipeline and circulation control strategy of the engine, and significant heating effect.

[0045] 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 with various modifications being 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 low-temperature starting device for a methanol engine, characterized in that, include: A gasoline supply system, located at the cylinder head of the engine, comprising: Multiple gasoline injectors are disposed at the intake manifold of the cylinder head; A gasoline rail, which is used to supply gasoline fuel to the plurality of gasoline injectors; A gasoline fine filter, through which gasoline fuel filtered by the gasoline fine filter enters the gasoline rail; and A fuel tank that supplies gasoline fuel to the fuel rail via the fuel filter; and The ECU controls the gasoline supply system to supply fuel to the engine during a cold start, enabling the engine to start normally.

2. The low-temperature starting device for a methanol engine as described in claim 1, characterized in that, It also includes a methanol supply system, which comprises: Multiple methanol injectors are disposed at the intake manifold of the cylinder head; A methanol rail line, used to supply methanol fuel to the plurality of methanol injectors; A methanol fine filter, through which methanol fuel is filtered, enters the methanol rail. A methanol tank, which supplies methanol fuel to the methanol rail line through the methanol fine filter; and A methanol pump, the inlet of which is connected to the methanol tank, and the outlet of which is connected to the inlet of the methanol fine filter; The ECU can control the injection quantity and pressure of methanol entering the intake manifold through the methanol pump and the plurality of methanol injectors.

3. The low-temperature starting device for a methanol engine as described in claim 2, characterized in that, The methanol supply system also includes: A methanol coarse filter, which is located inside the methanol tank or upstream of the inlet of the methanol pump; and A pressure control valve is located at the methanol pump, and the ECU can control the output pressure of the methanol pump through the pressure control valve.

4. The low-temperature starting device for a methanol engine as described in claim 2, characterized in that, There are two gasoline rails and two methanol rails, each gasoline rail including multiple gasoline injectors and each methanol rail including multiple methanol injectors.

5. The low-temperature starting device for a methanol engine as described in claim 4, characterized in that, The gasoline injector and the methanol injector inject gasoline or methanol according to the injection command pulse issued by the ECU. The injection start point is controlled by the start point of the command pulse, and the injection quantity is controlled by the width of the command pulse.

6. The low-temperature starting device for a methanol engine as described in claim 4, characterized in that, The injection pressure of the gasoline injector and the methanol injector is the common rail pressure, the methanol rail pressure is 5 bar, and the gasoline rail pressure is 4 bar.

7. The low-temperature starting device for a methanol engine as described in claim 3, characterized in that, The methanol supply system also includes a first heater, a second heater, and a third heater, which are arranged in series between the methanol pump and the methanol rail.

8. The low-temperature starting device for a methanol engine as described in claim 7, characterized in that, The methanol supply system also includes: A first temperature sensor is located at the outlet of the pressure control valve; A second temperature sensor is located at the outlet of the first heater; A third temperature sensor is located at the outlet of the second heater; and A fourth temperature sensor is located at the outlet of the third heater.

9. The low-temperature starting device for a methanol engine as described in claim 8, characterized in that, After the gasoline supply system has been running for a period of time and the engine coolant has reached a certain temperature, the ECU issues a switching command, the gasoline supply system stops running, and the methanol supply system starts running at the same time.

10. The low-temperature starting device for a methanol engine as described in claim 8, characterized in that, When the temperature detected by the first temperature sensor is less than or equal to the required operating temperature, the ECU will issue a command to start the first heater. When the temperature detected by the second temperature sensor is less than or equal to the required operating temperature, the ECU will issue a command to start the second heater. When the temperature detected by the third temperature sensor is less than or equal to the required operating temperature, the ECU will issue a command to the third heater to start heating; and When the temperature detected by the fourth temperature sensor is higher than a certain value required for operation, the ECU will issue a command to stop the first heater from heating. When the temperature detected by the fourth temperature sensor is still higher than a certain value required for operation after the first heater has stopped heating for a period of time, the ECU will issue a command to stop the second heater from heating. as well as When the first heater and the second heater have stopped heating for a period of time, if the temperature detected by the fourth temperature sensor is still higher than a certain value required for operation, the ECU will issue a command to stop the third heater from heating.

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