Formic acid removal system of methanol engine and automobile

Abstract

The invention belongs to the technical field of engines, and particularly relates to a formic acid removal system of a methanol engine and an automobile, the formic acid removal system comprises an air inlet pretreatment unit, and the air inlet pretreatment unit comprises an air inlet heater and an air inlet humidifier which are sequentially arranged on the air inlet side of the methanol engine; the air inlet heater and the air inlet humidifier correspondingly adjust the air inlet temperature and the air inlet humidity of air based on the environment temperature, so that combustible mixed gas formed by the air and methyl alcohol is fully combusted. In the formic acid removal system of the methanol engine, the air inlet pretreatment unit controls the temperature and humidity of the air, so that the air and the methanol can be uniformly mixed to form the combustible mixed gas, the combustible mixed gas is further ensured to be fully combusted in the methanol engine, the formic acid generation amount is reduced from the formic acid generation source, and the formic acid removal efficiency is improved. Corrosion of formic acid to the methanol engine can be effectively improved, and the overall reliability of the methanol engine is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of engines, and in particular to a formic acid removal system of a methanol engine and a vehicle. Background Art

[0002] A methanol engine is a methanol engine that uses methanol as its main fuel. While meeting the power performance of the original methanol engine, it uses methanol fuel, which has lower costs and produces less harmful gases, making the methanol engine more economical and environmentally friendly than traditional gasoline methanol engines.

[0003] Since methanol produces formic acid during the combustion process, formic acid will cause serious corrosion to the metal parts of the methanol engine, thereby affecting the overall reliability of the methanol engine. Summary of the invention

[0004] In order to improve the amount of formic acid generated in a methanol engine, the present invention provides a formic acid removal system for a methanol engine and a vehicle.

[0005] According to an embodiment of the present invention, a first aspect provides a formic acid removal system for a methanol engine, comprising an intake air pretreatment unit, wherein the intake air pretreatment unit comprises an intake air heater and an intake air humidifier sequentially arranged on the intake side of the methanol engine;

[0006] The intake air heater and the intake air humidifier adjust the intake air temperature and intake air humidity correspondingly based on the ambient temperature so that the combustible mixture formed by the air and methanol can be fully burned.

[0007] In some embodiments, the air intake heater adjusts the air intake temperature based on the ambient temperature, including:

[0008] When the ambient temperature is less than -15°C, the intake air heater adjusts the intake air temperature to 70°C to 80°C;

[0009] When -15°C≤ambient temperature<0°C, the intake air heater adjusts the intake air temperature to 60°C~70°C;

[0010] When 0°C≤ambient temperature<10°C, the intake air heater adjusts the intake air temperature to 50°C~60°C;

[0011] When the ambient temperature is 10°C ≤ 30°C, the intake air heater adjusts the intake air temperature to 30°C to 40°C;

[0012] When 30°C≤ambient temperature<40°C, the intake air heater adjusts the intake air temperature to 25°C~30°C.

[0013] In some embodiments, the intake humidifier adjusts the intake humidity of the air based on the ambient temperature, including:

[0014] When the ambient temperature is less than -15°C, the intake humidifier adjusts the intake humidity to 30% to 35%;

[0015] When -15°C ≤ ambient temperature < 0°C, the intake humidifier adjusts the intake humidity to 35% to 40%;

[0016] When 0°C≤ambient temperature<10°C, the intake humidifier adjusts the intake humidity to 40%~45%;

[0017] When the ambient temperature is 10°C ≤ 30°C, the intake humidifier adjusts the intake humidity to 45% to 50%;

[0018] When the ambient temperature is 30°C≤the ambient temperature<40°C, the intake air humidifier adjusts the intake air humidity to 50%-60%.

[0019] In some embodiments, the formic acid removal system further includes a combustion optimization unit, which includes a combustion controller and a fuel injector. The combustion controller adjusts the injection amount and injection timing of the fuel injector based on the load condition of the methanol engine.

[0020] In some embodiments, the displacement of the methanol engine is 1.5T, and the combustion controller adjusts the injection amount of the fuel injector based on the load condition of the methanol engine, including:

[0021] When the methanol engine is in an idling condition, the combustion controller controls the injection amount of the fuel injector in each working cycle to be 20 mg to 30 mg;

[0022] When the methanol engine is in a medium-low load condition, the combustion controller controls the injection amount of the fuel injector in each working cycle to be 30 mg to 50 mg;

[0023] When the methanol engine is in a high-load condition, the combustion controller controls the injection amount of the fuel injector in each working cycle to be 80 mg to 120 mg.

[0024] In some embodiments, the combustion controller adjusts the injection timing of the fuel injector based on the load condition of the methanol engine, including:

[0025] When the methanol engine is in idle condition, the injection advance angle is 20 to 30 degrees;

[0026] When the methanol engine is in medium and low load conditions, the injection advance angle is 10 to 20 degrees;

[0027] When the methanol engine is in high load condition, the injection advance angle is 5 to 10 degrees.

[0028] In some embodiments, the formic acid removal system further comprises an exhaust gas treatment unit, wherein the exhaust gas treatment unit comprises a formic acid adsorber, a formic acid catalytic decomposer and an exhaust gas post-processor which are sequentially arranged on the exhaust side of the methanol engine along the exhaust direction;

[0029] The formic acid adsorber is filled with activated carbon or molecular sieve; the formic acid catalytic decomposer is filled with a catalyst, which is made of a mixture of metal oxides and precious metals, wherein the metal oxides include copper oxide and manganese oxide, and the precious metals include platinum and palladium; the exhaust gas after-processor is a three-way catalytic converter.

[0030] In some embodiments, the air intake pretreatment unit further includes an air filter disposed on the air intake side of the air intake heater, wherein the air filter is provided with a high efficiency fiber filter paper to filter out impurities in the air with a particle size greater than 0.3 microns.

[0031] In some embodiments, the diameter of the nozzle hole of the fuel injector is less than or equal to 0.1 mm.

[0032] According to an embodiment of the present invention, a second aspect provides a vehicle, wherein the vehicle is equipped with a methanol engine and the formic acid removal system described above.

[0033] By adopting the formic acid removal system of the methanol engine of the present invention, the air intake pretreatment unit controls the temperature and humidity of the air so that the air and methanol can be evenly mixed to form a combustible mixture, thereby ensuring that the combustible mixture is fully burned in the methanol engine, reducing the amount of formic acid generated from the source of formic acid generation, and effectively improving the corrosion of formic acid to the methanol engine, thereby ensuring the overall reliability of the methanol engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a structural schematic diagram of the formic acid removal system of the methanol engine of this embodiment.

[0035] In the figure: a methanol engine 10; an air intake pretreatment unit 20; an air filter 21; an air intake heater 22; an air intake humidifier 23; a combustion optimization unit 30; a combustion controller 31; a fuel injector 32; an exhaust gas treatment unit 40; a formic acid adsorber 41; a formic acid catalytic decomposer 42; and an exhaust gas post-processor 43. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0037] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology, and are not used to limit the conditions under which the present invention can be implemented. Any structural modification, change in proportion or adjustment of size should still fall within the scope of the technical contents disclosed in the present invention without affecting the effects and purposes that can be achieved by the present invention.

[0038] The directions or positional relationships indicated by the terms "upper", "lower", "left", "right", "middle", "longitudinal", "lateral", "horizontal", "inner", "outer", "radial", "circumferential" and the like in this specification are based on the directions or positional relationships shown in the drawings and are only for the convenience of simplifying the description. They do not indicate or imply that the devices or elements referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0039] like Figure 1 As shown, this embodiment provides a formic acid removal system for a methanol engine, wherein the methanol engine 10 uses methanol as fuel, and methanol and air are mixed in a certain proportion to form a combustible mixture, and the combustible mixture is compressed and burned in the cylinder of the methanol engine 10 to generate heat energy, and the high-temperature and high-pressure gas generated by the combustion drives the piston of the methanol engine 10 to perform reciprocating linear motion, and the piston outputs mechanical energy to the outside through the crankshaft.

[0040] The formic acid removal system of this embodiment includes an intake pretreatment unit 20, a combustion optimization unit 30 and an exhaust gas treatment unit 40. The intake pretreatment unit 20 includes an air filter 21, an intake heater 22 and an intake humidifier 23 which are sequentially arranged on the intake side of the methanol engine 10 along the intake direction.

[0041] The air filter 21 of this embodiment is used to filter impurities in the air entering the methanol engine 10. The air filter 21 is preferably provided with a high-efficiency fiber filter paper to filter out impurities in the air with a particle size greater than 0.3 microns, thereby ensuring the cleanliness of the air entering the methanol engine 10.

[0042] The air intake heater 22 of this embodiment is used to heat the filtered air, and the air intake humidifier 23 is used to add water vapor to the air. The air intake heater 22 and the air intake humidifier 23 adjust the air intake temperature and intake humidity based on the ambient temperature.

[0043] Specifically, when the ambient temperature is less than -15°C, the methanol engine 10 is started in an extremely low temperature environment, the intake air heater 22 adjusts the intake air temperature to 70°C to 80°C, and the intake air humidifier 23 adjusts the intake air humidity to 30% to 35%. In an extremely low temperature environment, the volatility of methanol is severely limited, and the intake air heater 22 needs to heat the air to a range of 70°C to 80°C, so that the methanol in the extremely low temperature environment is quickly converted into a gaseous state by heat, so that the methanol and air are evenly mixed to form a combustible mixture, ensuring that the methanol engine 10 is started smoothly and reducing the formic acid generated due to incomplete combustion of methanol.

[0044] Considering that extremely low temperature environment easily causes water vapor to condense, thus affecting the combustion effect of the combustible mixture, the intake humidifier 23 at this time needs to adjust the intake humidity of the air to 30% to 35%. The air in this humidity range can not only provide a certain amount of water vapor assistance for methanol combustion, but also avoid problems such as poor intake or unstable combustion caused by water vapor condensation.

[0045] When -15°C≤ambient temperature<0°C, the methanol engine 10 is started in a relatively low temperature environment, the intake air heater 22 adjusts the intake air temperature to 60°C~70°C, and the intake air humidifier 23 adjusts the intake air humidity to 35%~40%. The methanol engine 10 has a lower temperature requirement for the air in a relatively low temperature environment, so the intake air heater 22 only needs to heat the air to this temperature range to make the methanol reach a suitable combustion condition, ensure the stable combustion of methanol, and thus reduce the probability of generating formic acid due to incomplete combustion. As the ambient temperature rises, the air can increase humidity appropriately, so that methanol and air are better mixed to form a combustible mixture, which can not only optimize the combustion of methanol and reduce the amount of formic acid generated, but also avoid condensation due to too high humidity in the air.

[0046] When 0°C≤ambient temperature<10°C, the methanol engine 10 is started in a conventional low temperature environment, the intake air heater 22 adjusts the intake air temperature to 50°C~60°C, and the intake air humidifier 23 adjusts the intake air humidity to 40%~45%. As the ambient temperature further increases, the vaporization and combustion conditions of methanol gradually improve, and when the intake air temperature and humidity of the air are controlled in this range, the combustion effect of methanol is better.

[0047] When the ambient temperature is 10°C≤<30°C, the methanol engine 10 is started at normal temperature, the intake air heater 22 adjusts the intake air temperature to 30°C-40°C, and the intake air humidifier 23 adjusts the intake air humidity to 45%-50%, and the combustion effect of methanol is better.

[0048] When the ambient temperature is 30°C≤<40°C, the methanol engine 10 is started in a high temperature environment, the intake air heater 22 adjusts the intake air temperature to 25°C~30°C, and the intake air humidifier 23 adjusts the intake air humidity to 50%~60%. Properly increasing the humidity at this ambient temperature can maintain the combustible mixture in a good state during the combustion process.

[0049] The combustion optimization unit 30 of this embodiment includes a combustion controller 31 and a fuel injector 32. Methanol is supplied to the methanol engine 10 through the fuel injector 32. The combustion controller 31 adjusts the injection amount and injection time of the fuel injector 32 based on the load condition of the methanol engine 10 to ensure that the methanol is fully burned. The nozzle diameter of the fuel injector 32 of this embodiment is preferably less than or equal to 0.1 mm, so that the methanol sprayed by the fuel injector 32 is in a spray shape, which can improve the uniformity of the mixture of methanol and air, and thus improve the combustion efficiency of the combustible mixture. It should be noted that the specific structure and control principle of the combustion controller 31 and the fuel injector 32 are existing technologies in the field of methanol engines 10, so this embodiment will not be repeated.

[0050] Taking the methanol engine 10 with a displacement of 1.5T as an example, when the methanol engine 10 is in an idle condition, the combustion controller 31 controls the injection amount of the fuel injector 32 in each working cycle to be 20 mg to 30 mg. The idle condition of this embodiment specifically refers to the state in which the methanol engine 10 maintains the lowest stable speed operation. At this time, the load of the methanol engine 10 is low and the speed is low, mainly to ensure that the methanol engine 10 can run smoothly without stalling, such as the state of the methanol engine 10 when the vehicle is parked and waiting, or the situation in which some equipment is in standby but keeps the methanol engine running, etc.

[0051] When the methanol engine 10 is in a medium-low load condition, the combustion controller 31 controls the injection amount of the fuel injector 32 in each working cycle to be 30 mg to 50 mg. The medium-low load condition of this embodiment specifically refers to the state that the methanol engine 10 needs a certain amount of power to maintain normal operation. At this time, the load and speed of the methanol engine 10 gradually increase, so it is necessary to appropriately increase the injection amount of methanol to meet the power demand, such as the scene where the vehicle is in normal driving on urban roads and general industrial equipment is in a conventional, non-full load operation state.

[0052] When the methanol engine 10 is in a high-load condition, the combustion controller 31 controls the injection amount of the fuel injector 32 in each working cycle to be 80 mg to 120 mg. The high-load condition of this embodiment is specifically that the methanol engine 10 is in a high-load operation state, at which the speed of the methanol engine 10 is high and the demand for methanol is large, such as when a vehicle needs to burst out a large power in a short time when overtaking at high speed, a heavy-loaded transport vehicle is fully loaded climbing a slope, and a large industrial equipment is fully loaded.

[0053] When the methanol engine 10 is in an idle condition, the injection advance angle is 20 to 30 degrees. In a low-speed methanol engine 10, the flow velocity and combustion velocity of the combustible mixture are relatively slow. In order to ensure that combustion preparations can be made before ignition, a larger injection advance angle is required. When the methanol engine 10 is in a medium-low load condition, the injection advance angle is 10 to 20 degrees. In a medium-speed methanol engine 10, the flow velocity and combustion velocity of the combustible mixture are relatively stable, and the injection advance angle of methanol can be appropriately close to the top dead center. When the methanol engine 10 is in a high-load condition, the injection advance angle is 5 to 10 degrees. In a high-speed methanol engine 10, the flow velocity and combustion velocity of the combustible mixture are relatively fast, and the injection advance angle of methanol needs to be further close to the top dead center.

[0054] The exhaust gas treatment unit 40 of this embodiment includes a formic acid adsorber 41, a formic acid catalytic decomposer 42 and an exhaust gas after-treatment device 43 which are sequentially arranged on the exhaust side of the methanol engine 10 along the exhaust direction. The formic acid adsorber 41 is preferably filled with activated carbon or molecular sieve as an adsorption material. When the adsorption material adsorbs formic acid to a saturated state, it can be regenerated by passing high-temperature steam or other regeneration methods to restore its adsorption capacity. The formic acid catalytic decomposer 42 is filled with a catalyst to decompose formic acid into carbon dioxide and water. The catalyst is preferably made of a mixture of metal oxides (such as copper oxide, manganese oxide, etc.) and precious metals (such as platinum, palladium, etc.) in proportion to ensure the catalytic effect. The exhaust gas after-treatment device 43 preferably uses a three-way catalytic converter, which can effectively catalyze conventional pollutants such as carbon monoxide and nitrogen oxides in the exhaust gas to ensure that the exhaust gas discharged meets environmental protection standards.

[0055] The formic acid removal system of this embodiment is optimized from three stages: air intake pretreatment, methanol combustion and exhaust gas emission. In the air intake pretreatment stage, the temperature and humidity of the air are controlled to ensure that the air can be evenly mixed with methanol to form a combustible mixture; in the methanol combustion stage, the injection amount and injection time of methanol are controlled to ensure that the combustible mixture formed by methanol and air is fully burned; in the air intake pretreatment stage and the methanol combustion stage, the amount of formic acid generated is reduced from the source of formic acid generation. In the exhaust gas emission stage, the emission of formic acid is reduced by absorbing and decomposing formic acid, which can effectively improve the corrosion of formic acid to the methanol engine 10 and ensure the overall reliability of the methanol engine 10.

[0056] It should be noted that the specific ranges of low speed, medium speed and high speed corresponding to the idle condition, medium and low load condition and high load condition in this embodiment need to be comprehensively judged according to the actual performance parameters and application scenarios of the methanol engine 10. The injection advance angle in this embodiment specifically refers to the crankshaft angle of the piston of the methanol engine 10 from the top dead center. Each working cycle of the methanol engine 10 specifically refers to the entire process of the methanol engine 10 completing the four strokes of intake, compression, power and exhaust.

[0057] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0058] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A formic acid removal system for a methanol engine, characterized in that: The invention comprises an intake air pretreatment unit (20), wherein the intake air pretreatment unit (20) comprises an intake air heater (22) and an intake air humidifier (23) which are sequentially arranged on the intake side of the methanol engine (10); The intake air heater (22) and the intake air humidifier (23) adjust the intake air temperature and intake air humidity of the air based on the ambient temperature so that the combustible mixture formed by the air and methanol can be fully burned.

2. The formic acid removal system according to claim 1, characterized in that: The air intake heater (22) adjusts the air intake temperature based on the ambient temperature, including: When the ambient temperature is less than -15°C, the intake air heater (22) adjusts the intake air temperature to 70°C to 80°C; When -15°C≤ambient temperature<0°C, the intake air heater (22) adjusts the intake air temperature to 60°C~70°C; When 0°C≤ambient temperature<10°C, the intake air heater (22) adjusts the intake air temperature to 50°C~60°C; When the ambient temperature is 10°C≤30°C, the intake air heater (22) adjusts the intake air temperature to 30°C-40°C; When the ambient temperature is 30°C≤40°C, the intake air heater (22) adjusts the intake air temperature to 25°C-30°C.

3. The formic acid removal system according to claim 1, characterized in that: The intake humidifier (23) adjusts the intake humidity of the air based on the ambient temperature, including: When the ambient temperature is less than -15°C, the intake humidifier (23) adjusts the intake humidity to 30% to 35%; When -15°C ≤ ambient temperature < 0°C, the intake humidifier (23) adjusts the intake humidity to 35% to 40%; When 0°C≤ambient temperature<10°C, the intake air humidifier (23) adjusts the intake air humidity to 40%-45%; When the ambient temperature is 10°C ≤ 30°C, the intake humidifier (23) adjusts the intake humidity to 45% to 50%; When the ambient temperature is 30°C≤40°C, the intake air humidifier (23) adjusts the intake air humidity to 50% to 60%.

4. The formic acid removal system according to any one of claims 1 to 3, characterized in that: The invention also comprises a combustion optimization unit (30), wherein the combustion optimization unit (30) comprises a combustion controller (31) and a fuel injector (32), wherein the combustion controller (31) adjusts the injection amount and injection timing of the fuel injector (32) based on the load condition of the methanol engine (10).

5. The formic acid removal system according to claim 4, characterized in that: The displacement of the methanol engine (10) is 1.5T, and the combustion controller (31) adjusts the injection amount of the fuel injector (32) based on the load condition of the methanol engine (10) including: When the methanol engine (10) is in an idling condition, the combustion controller (31) controls the injection amount of the fuel injection nozzle (32) in each working cycle to be 20 mg to 30 mg; When the methanol engine (10) is in a medium-low load condition, the combustion controller (31) controls the injection amount of the fuel injection nozzle (32) in each working cycle to be 30 mg to 50 mg; When the methanol engine (10) is in a high-load operating condition, the combustion controller (31) controls the injection amount of the fuel injection nozzle (32) in each working cycle to be 80 mg to 120 mg.

6. The formic acid removal system according to claim 4, characterized in that: The combustion controller (31) adjusts the injection timing of the fuel injector (32) based on the load condition of the methanol engine (10) including: When the methanol engine (10) is in an idling condition, the injection advance angle is 20 degrees to 30 degrees; When the methanol engine (10) is in a medium or low load condition, the injection advance angle is 10 degrees to 20 degrees; When the methanol engine (10) is in a high-load operating condition, the injection advance angle is 5 degrees to 10 degrees.

7. The formic acid removal system according to claim 1, characterized in that: It also includes an exhaust gas treatment unit (40), which includes a formic acid adsorber (41), a formic acid catalytic decomposer (42) and an exhaust gas post-processor (43) which are sequentially arranged on the exhaust side of the methanol engine (10) along the exhaust direction; The formic acid adsorber (41) is filled with activated carbon or molecular sieve; the formic acid catalytic decomposer (42) is filled with a catalyst, which is made of a mixture of metal oxides and precious metals, wherein the metal oxides include copper oxide and manganese oxide, and the precious metals include platinum and palladium; the exhaust gas after-treatment device (43) is a three-way catalytic converter.

8. The formic acid removal system according to claim 1, characterized in that: The air intake pretreatment unit (20) further comprises an air filter (21) arranged on the air intake side of the air intake heater (22), wherein the air filter (21) is provided with high-efficiency fiber filter paper for filtering out impurities in the air with a particle size greater than 0.3 micrometers.

9. The formic acid removal system according to claim 4, characterized in that: The diameter of the spray hole of the fuel injection nozzle (32) is less than or equal to 0.1 mm.

10. An automobile, characterized in that: The automobile is equipped with a methanol engine (10) and a formic acid removal system according to any one of claims 1 to 9.

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