Methanol engine cold starting device with magnetic-electric coupling heating function

Abstract

The invention belongs to the technical field of power equipment and methanol cold start, and particularly relates to a magnetic-electric coupling heating methanol engine cold start device which comprises a methanol preheating unit, an air preheating unit, an air inlet unit and an ECU (electronic control unit). The methanol preheating unit comprises a methanol box, a methanol magnetic heating device and an oil sprayer which are sequentially connected through a methanol pipeline; the air preheating unit comprises an air filter and an air heating device which are sequentially connected through an air pipeline; the air heating device and the oil sprayer are communicated with each other and are connected with the air inlet unit; the air heating device comprises a direct-flow preheating flow channel and a plurality of rotational-flow preheating flow channels arranged around the direct-flow preheating flow channel; and the electronic control unit is electrically connected with the methanol preheating unit and the air preheating unit. Through cooperation of rotational flow and direct flow, the air inlet pressure is increased, and meanwhile the enough air heat exchange area is guaranteed; the methanol magnetic heating device saves heating time, facilitates subsequent methanol droplet atomization, and solves the problem that cold start of an engine is difficult.

Description

Technical Field

[0001] The invention belongs to the technical field of power equipment and methanol cold start, and in particular relates to a methanol engine cold start device with magnetic-electric coupling heating. Background Art

[0002] In order to cope with the severe situation of the energy crisis, it is crucial to use energy efficiently and explore clean and renewable energy. Methanol, as a new type of clean fuel, can replace gasoline and diesel for use in many power equipment, which is particularly evident in motor vehicles. At the same time, as a good carrier of hydrogen, methanol has the characteristics of low boiling point, low cost, high octane number and physical and chemical properties close to gasoline, making it a favorable candidate for sustainable fuel. With the increasing use of methanol in the field of motor vehicles, its problems are gradually revealed. Among them, the difficulty of cold start caused by the high latent heat of vaporization of methanol is one of the important problems facing methanol engines. At present, technical researchers have alleviated the negative impact of methanol cold start through intake preheating, fuel preheating and improving the fuel spray effect.

[0003] In the prior art, most methods to solve methanol cold start problems use intake duct preheating technology. For example, the utility model patent with authorization announcement number CN220667695U discloses an intake duct preheating structure for a methanol engine cold start system. A good preheating effect is achieved by using a two-section intake pipe and a heating plate in direct contact with the air. This is feasible in principle and relatively convenient to disassemble and repair. However, compared to engines with higher volume power density requirements, direct heating of the heating plate in the intake duct also increases intake resistance. When it is necessary to overcome the intake resistance caused by the heating plate in the intake duct, a higher intake pressure is required, but the actual situation is that it is difficult to provide a higher intake pressure during cold start. In order to better solve the methanol cold start problem, it is necessary to provide an effective methanol engine cold start magnetic-electric coupled intake and fuel dual preheating device. Summary of the invention

[0004] The purpose of the present invention is to provide a methanol engine cold start device with magnetic-electric coupling heating. By adopting a swirl and direct current combined air heating device near the methanol injector in the intake duct, the intake pressure can be increased while ensuring sufficient heat exchange area between the heating plate and the incoming air, thereby improving the uniformity of air temperature. The methanol magnetic heating device not only saves heating time, but also facilitates the subsequent methanol droplet atomization, thereby solving the problem of difficult engine cold start.

[0005] To achieve the above-mentioned purpose, the present invention provides a methanol engine cold start device with magnetic-electric coupling heating, comprising a methanol preheating unit, an air preheating unit, an air intake unit and an ECU electronic control unit;

[0006] The methanol preheating unit comprises a methanol tank, a methanol magnetic heating device and a fuel injector which are sequentially connected through a methanol pipeline;

[0007] The air preheating unit comprises an air filter and an air heating device which are sequentially connected through an air pipeline; the air heating device is interconnected with the fuel injector and both are connected to the air intake unit; the air heating device comprises a direct current preheating flow channel and a plurality of swirl preheating flow channels arranged around the direct current preheating flow channel;

[0008] The ECU electronic control unit is electrically connected to the methanol preheating unit and the air preheating unit respectively.

[0009] Furthermore, the direct current preheating channel is a hollow cylindrical heating body, and the swirl preheating channel includes a circular insulating circumferential wall and a plurality of swirl wall surfaces which are sleeved on the outside of the hollow cylindrical heating body. The swirl wall surfaces are evenly distributed between the inner wall of the circular insulating circumferential wall and the outer wall of the hollow cylindrical heating body to form a plurality of swirl preheating channels.

[0010] Furthermore, the hollow cylindrical heating body and the swirl wall are both PCT heaters.

[0011] Furthermore, the air preheating unit also includes an air flow meter arranged between the air filter and the air heating device and a temperature sensor arranged between the air heating device and the injector.

[0012] Furthermore, the methanol magnetic heating device comprises a methanol bypass inner pipeline, a methanol bypass pipe sleeve, a heat conductive material, a coil and an iron core;

[0013] The coil is wound on the iron core, the methanol bypass pipe sleeve is wound on the outer wall of the coil, and the methanol bypass inner pipeline is wound and covered inside the methanol bypass pipe sleeve; one end of the methanol bypass inner pipeline is connected to the methanol tank, and the other end is connected to the injector.

[0014] Furthermore, a heat-conducting material is filled between the methanol bypass pipe sleeve and the methanol bypass inner pipeline, and the heat-conducting material is preferably magnesia sand.

[0015] Furthermore, magnetic particles are added to the methanol liquid flowing through the methanol magnetic heating device to promote the breakup of methanol droplets under the action of the magnetic field.

[0016] Furthermore, the methanol preheating unit also includes a temperature sensor, a methanol pump, a filter, a methanol flowmeter and a flame arrester which are sequentially arranged between the methanol magnetic heating device and the injector. The flame arrester is used to prevent the methanol temperature from being too high to form methanol vapor and flash back at the nozzle.

[0017] Furthermore, the ECU electronic control unit controls the temperature of the methanol and the air to be between 30°C and 50°C through temperature monitoring by a temperature sensor.

[0018] Furthermore, the intake unit includes an intake valve and a cylinder, and the preheated air and methanol are mixed at the front end of the intake valve and then enter the cylinder.

[0019] In general, the above technical solution conceived by the present invention has the following technical advantages compared with the prior art:

[0020] 1. The magnetic-electric coupling heating methanol engine cold start device provided by the present invention can ensure sufficient heat exchange area between the heating plate and the incoming air while increasing the intake pressure by using a swirl and direct current air heating device near the methanol injector in the intake duct, thereby improving the uniformity of air temperature. The use of a magnetic heating device for methanol not only saves heating time to meet the needs of different working conditions of the methanol engine, but also facilitates the subsequent atomization of methanol droplets, solving the problem of engine cold start difficulties. The coupling of the two heating effects increases the stability, economy and success rate of methanol cold start.

[0021] 2. The bypass methanol pipeline designed by the present invention can increase the contact time between the methanol fuel and the heated wall surface. Magnesia sand has the advantages of good thermal conductivity and low cost. Since the magnetic heating speed is very fast, direct heating will affect the mechanical properties of the pipeline and be difficult to control. Therefore, magnesia sand can quickly heat the inflow methanol while protecting the methanol pipeline. At the same time, the magnetic heater saves the actual heating time and promotes the atomization effect of the methanol fuel. In addition, the bypass pipeline saves the occupied space of the device while ensuring sufficient preheating.

[0022] 3. The air heating device is designed as a PTC swirl heating plate and a PTC cylindrical heating body. The swirl structure can increase the intake pressure while ensuring sufficient heat exchange area between the heating plate and the incoming air. The straight air inlet in the middle cylindrical part reduces the use of materials and the burden of intake pressure. At the outlet of the PTC heating device, the swirl preheated air and the direct current preheated air generated can be fully mixed and transfer heat to each other, ensuring uniform air temperature throughout the intake duct and preventing the intake duct from increasing mechanical stress due to uneven temperature and possibly causing cracks and reducing its mechanical properties.

[0023] 4. In the present invention, magnetic particles are added to the methanol liquid flowing through the methanol magnetic heating device under the condition of magnetic heating, so that the surface charge distribution and flow characteristics of the methanol droplets are changed under the action of the magnetic field, thereby promoting the breakup of the methanol droplets. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the overall structure of the methanol engine cold start device with magnetic-electric coupling heating provided by the present invention.

[0025] Figure 2 It is a structural schematic diagram of the air heating device of the present invention.

[0026] Figure 3 It is a structural schematic diagram of the methanol magnetic heating device of the present invention.

[0027] Throughout the drawings, the same reference numerals are used to denote the same elements or structures, wherein:

[0028] 1-power supply; 2-ECU electronic control unit; 3-circuit; 4-methanol tank; 5-temperature sensor; 6-methanol pump; 7-filter; 8-methanol flow meter; 9-flame arrester; 10-air filter; 11-air pipeline; 12-air flow meter; 13-injector; 14-intake valve;

[0029] 30-air heating device; 31-insulating layer; 32-swirl PTC heating sheet; 33-cylindrical PTC heating body; 34-swirl preheating channel; 35-DC preheating channel;

[0030] 300-methanol magnetic heating device; 301-methanol flow inner pipeline; 302-thermal conductive material; 303-methanol flow pipe sleeve; 304-coil; 305-iron core. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the 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. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0032] like Figures 1 to 3 As shown, the magnetic-electric coupling methanol cold start device of the embodiment of the present invention includes a methanol preheating unit, an air preheating unit, an air intake unit and an ECU electronic control unit 2.

[0033] Wherein, the methanol preheating unit comprises a methanol tank 4, a methanol magnetic heating device 300 and a fuel injector 13 which are sequentially connected through a methanol pipeline;

[0034] The air preheating unit includes an air filter 10 and an air heating device 30 which are sequentially connected through an air pipeline 11; the air heating device 30 is interconnected with the injector 13 and both are connected to the air intake unit; the air heating device 30 includes a direct current preheating flow channel 35 and a plurality of swirl preheating flow channels 34 arranged around the direct current preheating flow channel 35;

[0035] The air intake unit includes an air intake valve 14 and a cylinder, and the preheated air and methanol are mixed at the front end of the air intake valve 14 and then enter the cylinder;

[0036] The ECU electronic control unit 2 is electrically connected to the methanol preheating unit and the air preheating unit through lines 3 respectively.

[0037] With such arrangement, the swirl preheating channel 34 helps to mix the swirl gas evenly while increasing the intake pressure, relieves the pressure loss caused by the heating device in the intake duct, and prevents the intake duct from increasing mechanical stress and possibly cracking due to uneven temperature, which reduces its mechanical properties. The swirl gas is also beneficial for impacting and crushing the methanol droplets at the injection point, thereby improving the subsequent engine efficiency. The magnetic heating system is used in the fuel (methanol) supply system. Compared with the traditional preheating method, magnetic preheating not only saves heating time to meet the needs of different working conditions of the methanol engine, but also facilitates the subsequent methanol droplet atomization. The bypass duct saves the space occupied by the device while ensuring sufficient preheating.

[0038] Specifically, Figure 2 , the DC preheating channel 35 is a hollow cylindrical heating body ( Figure 2 The swirl preheating flow 34 includes a circular heat-insulating peripheral wall ( Figure 2 The middle insulation layer 31) and several swirl walls ( Figure 2 The swirl PTC heating plate 32 is evenly distributed between the inner wall of the circular insulation peripheral wall and the outer wall of the hollow cylindrical heating body, forming a plurality of swirl preheating channels 34 (for example, 4-8, preferably 6). The hollow cylindrical heating body and the swirl wall are both PCT heaters. In particular, the swirl PTC heating plate 32 is bent by 30° (i.e., the inclination angle with the radial plane of the hollow cylindrical heating body), and the swirl structure can ensure sufficient heat exchange area between the heating plate and the incoming air while increasing the intake pressure; the straight intake duct of the middle cylindrical part reduces the use of materials and the burden of intake pressure. At the outlet end of the PTC heating device, the generated swirl preheated air and direct current preheated air can be fully mixed and transfer heat to each other, ensuring that the air temperature is uniform throughout the intake duct, preventing the intake duct from increasing mechanical stress due to uneven temperature and possibly cracking, thereby reducing its mechanical properties.

[0039] In particular, the air preheating unit further includes an air flow meter 12 disposed between the air filter 10 and the air heating device 30 and a temperature sensor 5 disposed between the air heating device 30 and the injector 13. One end of the air pipe 11 is connected to the engine air filter 10, and the other end is connected to the intake valve 14.

[0040] The air flow meter 12 is used to detect the air flow in the air pipeline, and is combined with the methanol flow meter 8 to facilitate the control of the fuel-air ratio. The PTC air heating device 30 is used to heat the air introduced by the air filter 10. The air here can be mixed with a small amount of carbon monoxide and hydrogen, which is conducive to the combustion of methanol droplets in the cylinder to achieve a better combustion effect and improve the engine power. The PTC air heating device 30 is fed back by the rear temperature sensor 5 and the ECU electronic control unit 2 controls the air preheating temperature range of 30 to 50°C. Compared with magnetic heating, PTC has a more stable heating effect and the temperature rise is easier to control.

[0041] The PTC heating device 30 is arranged near the injector 13 in the air pipe 11, i.e., at the front end of the injector 13. The air enters from the air filter 10, and after the air flow is detected by the air flow meter 12, the PTC heating device 30 performs swirl and direct current heating simultaneously to reach the target preheating temperature. At the same time, the preheated air and the preheated methanol fuel are mixed with each other at the front end of the intake valve 14 and enter the cylinder together. The preheated air is used to keep the subsequent atomized methanol warm.

[0042] After the air enters the air filter 10, when passing through the PTC heating device 30, the air is heated simultaneously by the swirl preheating channel 34 and the direct current preheating channel 35. The PTC heating device 30 is arranged near the injector 13 to ensure that the air is always at the target preheating temperature in the air duct 11 before reaching the injector 13.

[0043] Specifically, Figure 1 and Figure 2 As shown, the air contacts the swirl PTC heating plate 32 through the swirl preheating channel 34. The sufficient preheating contact area reduces the length requirement of the heating system and saves costs. The design of the swirl preheating channel 34 increases the intake pressure and solves the problem of pressure obstruction caused by the built-in heater in the intake channel. The air passes through the direct current preheating channel 35, which not only saves the cost of the materials required for the middle part, but also ensures that the air is fully preheated while reducing pressure loss.

[0044] Specifically, Figure 1 and Figure 2 As shown, part of the air is heated by the swirl PTC heating sheet 32 ​​through the swirl preheating channel 34, and part of the air is heated by the cylindrical PTC heating body 33 through the DC preheating channel 35. The two parts are preheated simultaneously. At the outlet of the PTC heating device, the DC preheated air generated can be impacted by the swirl preheating air and evenly mixed and heat exchanged with each other, ensuring the uniformity of the preheated air temperature and reducing the possibility of cracks in the air intake duct and the reduction of mechanical properties due to uneven temperature. At the same time, the swirl preheated air is also conducive to the breakup and atomization of methanol droplets.

[0045] See also Figure 1 and 3, one end of the methanol bypass pipeline 301 is connected to the methanol tank 4, and the other end is connected to the methanol pump 6. After passing through the methanol magnetic heating device 300, the liquid methanol absorbs heat to become liquid methanol with a certain temperature. The temperature sensor 5 monitors in real time and feeds back to the ECU electronic control unit 2 to control the temperature range of 30 to 50°C. The methanol magnetic heating device 300 is used to heat the methanol liquid. Since the magnetic heating speed responds very quickly, the purpose of preheating the methanol can be achieved in a very short time. The preheated methanol fuel is filtered out of the residue (impurities in the methanol) by the filter 7, and the real-time flow rate can be reflected by the subsequent methanol flowmeter 8, and the real-time data of the air flowmeter 12 can achieve the purpose of controlling the fuel-air ratio. When the ECU electronic control unit 2 is damaged and the magnetic heating temperature cannot be controlled, the flame arrester 9 can timely prevent the dangerous situation of excessive methanol temperature to form methanol vapor and flashback at the nozzle.

[0046] Specifically, Figure 1 As shown, the methanol magnetic heating device 300 is arranged in the fuel supply system. After being extracted by the methanol pump 6, it flows around the methanol magnetic heating device 300 for preheating, and then passes through the subsequent methanol pipeline to the injector 13 for injection and atomization in the intake duct.

[0047] Specifically, Figure 1 and Figure 3 As shown, methanol fuel is extracted by a methanol pump 6, heated by a methanol magnetic heating device 300, filtered by a filter screen 7, and enters a fuel injector 13 for spraying and atomization.

[0048] The coil 304 is wound around the iron core 305, and generates heat energy through electromagnetic induction to heat the methanol fuel passing through the methanol bypass inner pipe 301. The methanol fuel is preheated through the methanol bypass inner pipe 301. The methanol bypass inner pipe 301 is configured as a bypass pipe to fully heat the liquid methanol on the periphery. The bypass formed in the pipe can evenly mix the inner layer methanol with the outer layer methanol to achieve the effect of internal heat exchange.

[0049] The methanol bypass pipe sleeve 303 is in direct contact with the magnetic heating coil 304. Considering the overheating caused by the extremely fast temperature response of the heating coil 304, magnesium oxide sand is added as a thermal conductive material 302 between the methanol bypass pipe sleeve 303 and the methanol bypass inner pipeline 301. Magnesium oxide sand has the advantages of good thermal conductivity and low cost. Since the magnetic heating speed is very fast, direct heating will affect the mechanical properties of the pipeline and be difficult to control. Therefore, magnesium oxide sand can quickly heat the inner flowing methanol while protecting the methanol pipeline.

[0050] In particular, in the case of magnetic heating, magnetic particles are added to the methanol liquid flowing through the methanol magnetic heating device to change the surface charge distribution and flow characteristics of the methanol droplets under the action of the magnetic field, thereby promoting the breakup of the methanol droplets. The magnetic particles can be fixed on the filter screen by setting a filter screen in the methanol bypass inner pipeline 301 to prevent the magnetic particles from being affected by the flow of the methanol liquid.

[0051] The response speed of magnetic heating is much faster than that of PTC heating, so the target preheating temperature can be reached in a very short time. At the same time, magnetism is conducive to the breakup of droplets, providing auxiliary effects for the rapid atomization and reduction of atomized particle size of subsequent methanol fuel after injection through the injector 13.

[0052] Therefore, the working principle of the embodiment of the present invention is as follows. The entire invention is divided into a PTC air heating stage, a methanol fuel heating stage and a premixing stage:

[0053] PTC air heating stage: air enters the air pipe 11 through the air filter 10, and enters the PTC heating section after the flow rate is measured by the air flow meter 12. The PTC heating device 30 is divided into two parts, swirl and direct current, to preheat the air at the same time, and feedback control is performed through the temperature sensor 5 to ensure that the air temperature is maintained at 30-50°C.

[0054] Methanol fuel heating stage: Methanol fuel is drawn by the methanol pump 6 and enters the methanol magnetic heating device 300 for circumferential preheating. Feedback control is performed through the temperature sensor 5 to maintain the temperature at 30° to 50°. The preheated methanol fuel is filtered out of solid impurities through the filter 7, and the flow rate is measured by the methanol flowmeter 8 before entering the injector 13 for high-pressure atomization injection.

[0055] Premixing stage: The atomized methanol droplets obtained by the injector 13 are mixed with the preheated air components and further broken up, and then enter the cylinder through the intake valve 14 for combustion.

[0056] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A methanol engine cold start device with magnetic-electric coupling heating, characterized in that: It includes a methanol preheating unit, an air preheating unit, an air intake unit and an ECU electronic control unit; The methanol preheating unit comprises a methanol tank, a methanol magnetic heating device and a fuel injector which are sequentially connected through a methanol pipeline; The air preheating unit comprises an air filter and an air heating device which are sequentially connected through an air pipeline; the air heating device is interconnected with the fuel injector and both are connected to the air intake unit; the air heating device comprises a direct current preheating flow channel and a plurality of swirl preheating flow channels which are arranged around the direct current preheating flow channel; The ECU electronic control unit is electrically connected to the methanol preheating unit and the air preheating unit respectively.

2. The magnetic-electric coupling heating methanol engine cold start device according to claim 1, characterized in that: The direct current preheating channel is a hollow cylindrical heating body, and the swirl preheating channel includes a circular insulation wall and a plurality of swirl wall surfaces which are sleeved on the outside of the hollow cylindrical heating body. The swirl wall surfaces are evenly distributed between the inner wall of the circular insulation wall and the outer wall of the hollow cylindrical heating body to form a plurality of swirl preheating channels.

3. The magnetic-electric coupling heating methanol engine cold start device according to claim 2, characterized in that: The hollow cylindrical heating body and the swirl wall are both PCT heaters.

4. The magnetic-electric coupling heating methanol engine cold start device according to any one of claims 1 to 3, characterized in that: The air preheating unit further includes an air flow meter disposed between the air filter and the air heating device and a temperature sensor disposed between the air heating device and the fuel injector.

5. The magnetic-electric coupling heating methanol engine cold start device according to claim 1, characterized in that: The methanol magnetic heating device comprises a methanol bypass inner pipeline, a methanol bypass pipe sleeve, a heat conductive material, a coil and an iron core; The coil is wound on the iron core, the methanol bypass pipe sleeve is wound on the outer wall of the coil, and the methanol bypass inner pipeline is wound and covered inside the methanol bypass pipe sleeve; one end of the methanol bypass inner pipeline is connected to the methanol tank, and the other end is connected to the injector.

6. The magnetic-electric coupling heating methanol engine cold start device according to claim 5, characterized in that: A heat-conducting material is filled between the methanol bypass pipe sleeve and the methanol bypass inner pipeline, and the heat-conducting material is preferably magnesia sand.

7. The magnetic-electric coupling heating methanol engine cold start device according to claim 5, characterized in that: Magnetic particles are added to the methanol liquid flowing through the methanol magnetic heating device to promote the breakup of methanol droplets under the action of a magnetic field.

8. The magnetic-electric coupling heating methanol engine cold start device according to claim 1, characterized in that: The methanol preheating unit also includes a temperature sensor, a methanol pump, a filter, a methanol flowmeter and a flame arrester which are sequentially arranged between the methanol magnetic heating device and the injector. The flame arrester is used to prevent the methanol temperature from being too high to form methanol vapor and flash back at the nozzle.

9. The magnetic-electric coupling heating methanol engine cold start device according to claim 1, characterized in that: The ECU electronic control unit controls the temperature of the methanol and the air at 30-50° C. through temperature monitoring by a temperature sensor.

10. The magnetic-electric coupling heating methanol engine cold start device according to claim 1, characterized in that: The air intake unit comprises an air intake valve and a cylinder. The preheated air and methanol are mixed at the front end of the air intake valve and then enter the cylinder.

Images