Compression ignition type methanol engine and control method

Abstract

The invention provides a compression ignition type methanol engine which comprises an air cylinder and a piston located in the air cylinder, a combustion chamber is defined between the air cylinder and the top of the piston, and the compression ignition type methanol engine further comprises an air inlet part, an oil sprayer and a glow plug. The air inlet part is arranged at the top of the cylinder, communicates with the combustion chamber and is suitable for guiding outside air into the combustion chamber. The oil sprayer is arranged at the top of the air cylinder and suitable for spraying methanol fuel to the combustion chamber so as to form mixed gas with external air. The glow plug is installed on the top of the air cylinder, the glow plug is provided with a heating end which extends into the combustion chamber to heat the mixed gas, and the heating end is constructed to generate displacement close to or away from the oil sprayer in response to at least one of the engine rotating speed, the accelerator pedal opening degree and the air inlet temperature.

Description

Technical Field

[0001] The present disclosure relates to the technical field of engines and engine control, and more specifically, to a compression ignition methanol engine and a control method thereof. Background Art

[0002] With the rapid development of the economy, the demand for power in transportation, industrial production and other fields is growing. In this context, the innovation and improvement of engine technology has become the research and development focus of scientific research institutions and enterprises in various countries. At the same time, as the source of power for the engine, the quality, combustion performance and environmental protection characteristics of fuel have a decisive effect on the performance and environmental impact of the engine. Engine technology has undergone many changes, such as turbocharging, direct injection, and mixed injection technology, which have improved the power density, fuel economy and emission performance of the engine. However, traditional engines still have certain limitations during operation, such as high fuel consumption and heavy emission pollution. In recent years, clean energy such as biofuels, natural gas, and hydrogen energy have gradually attracted attention. These new fuels have the advantages of low pollutant emissions and high calorific value during the combustion process. Therefore, developing engines that match new fuels has become the current development trend.

[0003] As an oxygen-containing organic compound, methanol has the characteristics of complete combustion, low pollution emissions, and high calorific value, making it an ideal substitute for traditional petroleum-based fuels. At the same time, the ignition characteristics, anti-knock characteristics, and volatility of methanol are similar to those of gasoline, which makes the working principle of methanol engines similar to that of traditional gasoline engines, usually spark-ignition engines. However, the thermal efficiency of spark-ignition engines is low, making it difficult to give full play to the calorific value advantages of methanol.

[0004] Traditional compression ignition methanol engines have problems with uneven mixture, unstable ignition, and excessive emissions. In related technologies, methanol can be ignited by diesel, but this requires the configuration of two fuel systems, which is complex and costly; or the ignition stability can be improved by heating the intake air, but this will affect the charging efficiency and high-load operation stability. Therefore, how to improve the ignition stability of compression ignition methanol engines has become a technical problem that needs to be solved urgently. Summary of the invention

[0005] In view of this, the present disclosure provides a compression ignition methanol engine, which can adjust the heating power according to different operating conditions and improve the ignition stability during the entire operation of the engine.

[0006] In order to achieve the above-mentioned purpose, the present invention provides a compression ignition methanol engine, including a cylinder and a piston located inside the above-mentioned cylinder, a combustion chamber is defined between the above-mentioned cylinder and the top of the above-mentioned piston, and also includes: an intake portion, arranged at the top of the above-mentioned cylinder and connected to the above-mentioned combustion chamber, suitable for guiding external air into the above-mentioned combustion chamber; an injector, arranged at the top of the above-mentioned cylinder, suitable for injecting methanol fuel into the above-mentioned combustion chamber to form a mixture with the air from the outside; an electric glow plug, installed at the top of the above-mentioned cylinder, the above-mentioned electric glow plug has a heating end extending into the above-mentioned combustion chamber to heat the above-mentioned mixture, and the above-mentioned heating end is configured to generate a displacement close to or away from the above-mentioned injector in response to at least one of the engine speed, the accelerator pedal opening and the intake temperature.

[0007] According to an embodiment of the present disclosure, the glow plug comprises: a shell having an open end located in the positioning hole of the cylinder and a closed end opposite to the open end; and a heating core extending from the shell through the open end into the combustion chamber.

[0008] According to an embodiment of the present disclosure, one end of the heating core extending into the combustion chamber is configured as the heating end, and the other end of the heating core is configured to approach or move away from the closed end of the shell along a first direction under the action of magnetic force.

[0009] According to an embodiment of the present disclosure, a accommodating cavity is formed inside the shell, and the accommodating cavity is filled with a fluid medium. The heating core is configured to reciprocate along a second direction perpendicular to the first direction in response to the extrusion of the fluid medium.

[0010] According to an embodiment of the present disclosure, the above-mentioned accommodating chamber includes a first accommodating chamber and a second accommodating chamber, and the above-mentioned first accommodating chamber and the above-mentioned second accommodating chamber are separated by the above-mentioned heating core and are connected through an oil storage tank.

[0011] According to an embodiment of the present disclosure, it also includes an exhaust portion, which is arranged at the top of the above-mentioned cylinder and is connected to the above-mentioned combustion chamber, and is suitable for guiding the exhaust gas to be discharged from the above-mentioned combustion chamber.

[0012] According to an embodiment of the present disclosure, a power supply device is also included, which is suitable for supplying power to the above-mentioned glow plug.

[0013] According to an embodiment of the present disclosure, the power supply device includes: an impeller, arranged in the exhaust portion, and configured to rotate driven by the exhaust gas; a generator, connected to the impeller, and suitable for converting the kinetic energy output by the impeller into electrical energy; and a battery, suitable for storing the electrical energy of the generator and supplying power to the glow plug.

[0014] The present disclosure also provides a compression ignition methanol engine control method, which adopts the compression ignition methanol engine in any of the above embodiments, and includes: obtaining engine speed and accelerator pedal opening information to determine the engine operating conditions; based on the above operating conditions, determining the distance between the intersection of the electric glow plug axis and the cylinder top and the injector.

[0015] According to an embodiment of the present disclosure, it also includes: obtaining the engine intake temperature, and adjusting the temperature of the above-mentioned electric glow plug and the length of the heating end extending into the above-mentioned cylinder according to the above-mentioned operating conditions and the above-mentioned intake temperature.

[0016] The compression ignition methanol engine provided by the present disclosure heats the methanol mixture by configuring a glow plug, and adjusts the position of the heating end of the glow plug according to at least one of the engine speed, the accelerator pedal opening and the intake air temperature, so that the heating power of the glow plug for the methanol mixture is adapted to the engine operating conditions, effectively improving the ignition stability during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The above and other objects, features and advantages of the present disclosure will become more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0018] Figure 1 is an overall schematic diagram of a compression ignition methanol engine provided by the present disclosure;

[0019] Figure 2 yes Figure 1 An enlarged view of the glow plug in the exemplary embodiment shown;

[0020] Figure 3 It is a schematic diagram of the principle of the heating core moving along the second direction in the compression ignition methanol engine provided by the present disclosure;

[0021] Figure 4 is a top view of the compression ignition methanol engine of the present disclosure, showing the positional relationship between the injector and the heating end of the glow plug;

[0022] Figure 5 is a flow chart of the compression ignition methanol engine control method provided by the present disclosure;

[0023] Figure 6 yes Figure 5 A schematic diagram of the control logic in an exemplary embodiment is shown.

[0024] In the drawings, the meanings of the reference numerals are as follows:

[0025] 1. Cylinder;

[0026] 11. Piston;

[0027] 2. Air intake;

[0028] 3. Fuel injector;

[0029] 4. Glow plug;

[0030] 40. Heating end;

[0031] 41. Shell;

[0032] 411, open end;

[0033] 412, closed end;

[0034] 413, first accommodating chamber;

[0035] 414, second accommodating chamber;

[0036] 415. Oil storage tank;

[0037] 42. Heating core;

[0038] 5. Exhaust section;

[0039] 6. Power supply device;

[0040] 61. Impeller;

[0041] 62. Generator;

[0042] 63. Battery. DETAILED DESCRIPTION

[0043] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present disclosure. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0044] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0045] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification and should not be interpreted in an idealized or overly rigid manner.

[0046] When using expressions such as "at least one of A, B, and C, etc.", they should generally be interpreted according to the meaning of the expression commonly understood by those skilled in the art (for example, "a system having at least one of A, B, and C" should include but is not limited to a system having A alone, B alone, C alone, A and B, A and C, B and C, and / or A, B, C, etc.).

[0047] Figure 1 is an overall schematic diagram of the compression ignition methanol engine provided by the present disclosure, Figure 2 yes Figure 1 An enlarged view of the glow plug is shown in the exemplary embodiment.

[0048] The embodiment of the present disclosure provides a compression ignition methanol engine, comprising a cylinder 1 and a piston 11 located inside the cylinder 1, wherein a combustion chamber is defined between the cylinder 1 and the top of the piston 11. Figure 1-Figure 2 As shown, the compression ignition methanol engine also includes an intake part 2, an injector 3 and a glow plug 4. The intake part is arranged at the top of the cylinder 1 and communicated with the combustion chamber, and is suitable for guiding the outside air into the combustion chamber. The injector 3 is arranged at the top of the cylinder 1, and is suitable for injecting methanol fuel into the combustion chamber to form a mixture with the air from the outside. The glow plug 4 is installed at the top of the cylinder 1, and the glow plug 4 has a heating end 40 extending into the combustion chamber to heat the mixture, and the heating end 40 is configured to generate a displacement close to or away from the injector 3 in response to at least one of the engine speed, the accelerator pedal opening and the intake temperature.

[0049] In such an embodiment, air enters the combustion chamber through the air intake 2, and methanol fuel is sprayed into the combustion chamber through the fuel injector 3 to form a methanol mixture in the combustion chamber. During the operation of the engine, the engine speed, the accelerator pedal opening and the intake temperature information are collected in real time. When at least one of them changes, the heating end 40 of the glow plug 4 produces a corresponding displacement to approach or move away from the fuel injector 3, thereby adjusting the heating power of the methanol mixture according to the operation of the engine, so that the ignition stability of the compression ignition methanol engine during the entire operation process is effectively improved.

[0050] In an exemplary embodiment, the heating end 40 is further configured to generate a temperature change in response to at least one of an engine speed, an accelerator pedal opening, and an intake air temperature, so as to change the heating power to the methanol mixed gas.

[0051] According to an embodiment of the present disclosure, the engine speed is obtained by a crankshaft position sensor, the accelerator pedal opening is obtained by an accelerator pedal sensor, and the intake air temperature is obtained by an intake air temperature sensor arranged in the intake part 2. The compression ignition methanol engine also includes an electronic control unit for receiving information / signals sent by the above sensors and sending action instructions to the glow plug 4 after processing.

[0052] In an exemplary embodiment, the glow plug 4 includes a housing 41 and a heating core 42. The housing 41 has an open end 411 located in a positioning hole of the cylinder 1 and a closed end 412 opposite to the open end 411. The heating core 42 extends from the housing 41 through the open end 411 into the combustion chamber.

[0053] In such an embodiment, reference Figure 2 As shown, a positioning hole is provided on the cylinder 1, and the open end 411 of the shell 41 is installed in the positioning hole, and the installation method includes but is not limited to threaded connection, so that the shell 41 and the cylinder 1 remain relatively fixed. The heating core 42 is arranged in the shell 41 and extends into the combustion chamber to heat the methanol mixed gas. The closed end 412 of the shell 41 is used to limit the heating core 42 to prevent the heating core 42 from being pushed out of the shell 41 when the pressure in the combustion chamber increases.

[0054] According to an embodiment of the present disclosure, one end of the heating core 42 extending into the combustion chamber is configured as the heating end 40, and the other end of the heating core 42 is configured to approach or move away from the closed end 412 of the shell 41 along a first direction under the action of magnetic force.

[0055] In such an embodiment, reference Figure 2 As shown, the first end of the heating core 42 is configured as the heating end 40, and the second end of the heating core 42 is moved close to or away from the closed end 412 of the shell 41 under the action of magnetic force, so as to drive the heating core 42 to reciprocate along the first direction, that is, the axial direction of the shell 41 or the heating core 42, so that the heating end 40 can be close to or away from the injector.

[0056] Furthermore, a permanent magnet is provided at the closed end 412 , and a magnetic induction coil is wound around the second end of the heating core 42 , and the moving direction of the heating core 42 is switched by changing the direction of the current in the magnetic induction coil.

[0057] More specifically, the heating core 42 is constructed as a cylinder, the cross-section of the open end 411 of the shell 41 is constructed as a ring, and a wear-resistant material coating is provided on the inner wall of the open end 411. The wear-resistant material includes but is not limited to graphite, so as to reduce the movement resistance of the heating core 42 while having a longer service life.

[0058] In some other embodiments, the heating core 42 includes a protective shell and an electric heating chip disposed in the protective shell, and a heat-conducting material is filled between the electric heating chip and the protective shell to transfer the heat of the electric heating chip to the protective shell.

[0059] According to an embodiment of the present disclosure, the electric heating chip adopts a silicon nitride ceramic heating chip, which has high thermal conductivity and thermal stability and can meet the heating requirements of higher temperatures. The position of the silicon nitride ceramic heating chip can be arranged appropriately close to the heating end 40. The protective shell is made of stainless steel or other high temperature resistant materials. The thermal conductive material includes but is not limited to the use of high temperature resistant ceramic glue, such as HR-8767A alumina high temperature resistant glue, which is preferably high in thermal conductivity.

[0060] Figure 3 It is a schematic diagram of the principle of the heating core moving along the second direction in the compression ignition methanol engine provided by the present disclosure.

[0061] In an exemplary embodiment, a receiving chamber is formed inside the shell 41, and the receiving chamber is filled with a fluid medium. The heating core 42 is configured to reciprocate along a second direction perpendicular to the first direction in response to the extrusion of the fluid medium.

[0062] In such an embodiment, by filling or releasing the fluid working medium into the accommodating cavity, the heating core 42 is squeezed by the fluid working medium and reciprocates along the second direction perpendicular to the first direction (i.e., the axial direction), so that the heating end 40 can be close to or away from the injector. Figure 3 As shown, the housing 41 is installed obliquely on the top of the cylinder 1. In this embodiment, the extension direction of the axis of the cylinder 1 is taken as the vertical direction, and the direction perpendicular to the axis is taken as the horizontal direction, that is, there is a certain angle between the axial direction and the vertical direction. When the heating core 42 moves in the axial direction, the horizontal distance and the vertical distance between the heating end 40 and the injector 3 will change, and the range of movement of the heating core 42 in the axial direction is large, so it can be used as a pre-adjustment or a first-level adjustment. When the heating core 42 moves in the second direction, the horizontal distance and the vertical distance between the heating end 40 and the injector 3 will also change, but limited by the caliber of the opening end 411 of the housing 41, the range of movement of the heating core 42 in the second direction is small, so it can be used as a second-level adjustment.

[0063] In some other embodiments, the housing 41 may also be installed on the top of the cylinder 1 in the vertical direction, that is, the axial direction is parallel to the vertical direction, so that the control logic of the electronic control unit can be simplified. However, in this case, the axial movement of the heating core 42 cannot cause the heating end 40 to produce a horizontal displacement, so when designing the installation position of the housing 41, it should be considered that the horizontal displacement range of the heating end 40 can meet the adjustment requirements.

[0064] Reference Figure 3 According to an embodiment of the present disclosure, the accommodating chamber includes a first accommodating chamber 413 and a second accommodating chamber 414 . The first accommodating chamber 413 and the second accommodating chamber 414 are separated by a heating core 42 and are connected through an oil storage tank 415 .

[0065] In such an embodiment, the fluid medium includes but is not limited to oil, and the volumes of the first accommodating chamber 413 and the second accommodating chamber 414 change with the filling / discharging of the fluid medium. Specifically, the oil storage tank 415 is connected to the first accommodating chamber 413 and the second accommodating chamber 414 through a plurality of oil pumps. Figure 3 For example, when the heating core 42 needs to move to the left, the oil pump on the left oil circuit pumps the oil in the first accommodating chamber 413 into the oil storage tank 415, and the oil pump on the right oil circuit pumps the oil in the oil storage tank 415 into the second accommodating chamber 414. At this time, the volume of the first accommodating chamber 413 decreases, and the volume of the second accommodating chamber 414 increases, and the heating core 42 moves to the left. When the heating core 42 needs to move to the right, the process and the principles involved are the same as when moving to the left, and will not be described in detail here. Figure 3 In FIG. 1 , the dotted line portion indicates the position of the heating core 42 after displacement.

[0066] In an exemplary embodiment, the compression ignition methanol engine further includes an exhaust portion 5, which is disposed at the top of the cylinder 1 and communicates with the combustion chamber and is suitable for guiding the exhaust gas to be discharged from the combustion chamber.

[0067] In such an implementation, Figure 1 As shown, the air intake portion 2 and the exhaust portion 5 are symmetrically arranged on the top of the cylinder 1 to realize the air intake and exhaust of the engine.

[0068] More specifically, the intake part 2 includes an intake manifold and an intake valve, the intake valve is used to switch the on-off state between the intake manifold and the combustion chamber, and the intake air temperature sensor is arranged in the intake manifold. The exhaust part 5 includes an exhaust valve and an exhaust pipe, and the exhaust valve is used to control the on-off state between the exhaust pipe and the combustion chamber.

[0069] According to an embodiment of the present disclosure, the compression ignition methanol engine further comprises a power supply device 6 adapted to supply power to the glow plug 4 .

[0070] In such an embodiment, the power supply device 6 is configured to supply power to at least one of the magnetic induction coil, the electric heating chip and the oil pump.

[0071] Furthermore, the power supply device 6 includes an impeller 61, a generator 62 and a battery 63. The impeller 61 is arranged in the exhaust portion 5 and is configured to rotate under the drive of the exhaust gas. The generator 62 is connected to the impeller 61 and is suitable for converting the kinetic energy output by the impeller 61 into electrical energy. The battery 63 is suitable for storing the electrical energy of the generator 62 and supplying power to the glow plug 4.

[0072] In such an embodiment, the impeller 61 is arranged in the exhaust pipe of the exhaust part 5. When the exhaust gas is discharged along the exhaust pipe, the impeller 61 rotates driven by the exhaust gas flow. The impeller 61 can be directly connected to the rotating shaft of the generator 62 to transfer kinetic energy, or it can transfer kinetic energy through gears or belts. After the generator 62 converts the kinetic energy into electrical energy, it is output to the battery 63 for storage. The battery 63 directly supplies power to the electric heating chip and the oil pump in the electric glow plug 4. When supplying power to the magnetic induction coil, a double-pole double-throw relay is also required to change the direction of the current.

[0073] Figure 4 is a top view of the compression ignition methanol engine disclosed herein, showing the positional relationship between the injector and the heating end of the glow plug, Figure 5 is a flow chart of the compression ignition methanol engine control method provided by the present disclosure, Figure 6 yes Figure 5 A schematic diagram of the control logic in an exemplary embodiment is shown.

[0074] The exemplary embodiment of the present disclosure also provides a control method for a compression ignition methanol engine, using the compression ignition methanol engine in any of the above embodiments, such as Figure 5 As shown, the method includes steps S100-S200.

[0075] Step S100: Obtain engine speed and accelerator pedal opening information to determine the engine operating condition.

[0076] Step S200: Determine the distance between the axis of the glow plug 4 and the junction of the top of the cylinder 1 and the injector 3 according to the operating conditions.

[0077] For example, Figure 4 The positional relationship and distance between the injector 3 and the heating end of the glow plug 4 are shown in detail.

[0078] According to the embodiments of the present disclosure, Figure 5 As shown, the method further includes step S300, obtaining the engine intake temperature, and adjusting the temperature of the glow plug 4 and the length of the heating end 40 extending into the cylinder 1 according to the operating status and the intake temperature.

[0079] Specifically, when the detected speed is less than the preset speed and the intake temperature is lower than the first preset temperature, the engine is determined to be in the first operating condition, the above-mentioned spacing is adjusted to the first spacing, the length of the heating end 40 extending into the cylinder 1 is the first length, and the temperature of the glow plug 4 is the first heating temperature.

[0080] Exemplarily, the preset rotation speed is 1000 rad / min, the first preset temperature is 0° C., the first spacing is 10 mm, the first length is 25 mm, and the first heating temperature is 1500K.

[0081] When the detected speed is greater than the preset speed, the operating condition is determined by the accelerator pedal opening. For details, please refer to Figure 6 shown.

[0082] If the accelerator pedal opening is less than 20%, it is determined that the engine is in the second operating condition, and the above distance is adjusted to the second distance. Exemplarily, the second distance is 15 mm.

[0083] If the accelerator pedal opening is between 20% and 70%, it is determined that the engine is in the third operating condition, and the above distance is adjusted to the third distance. Exemplarily, the third distance is 20 mm.

[0084] If the accelerator pedal opening is greater than 70%, it is determined that the engine is in the fourth operating condition, and the above distance is adjusted to the fourth distance. Exemplarily, the fourth distance is 25 mm.

[0085] In such an embodiment, as the accelerator pedal opening continues to increase, the injection amount and injection pressure also continue to increase, so the distance between the axis of the glow plug 4 and the junction of the top of the cylinder 1 and the injector 3 increases accordingly to avoid pre-ignition.

[0086] In some other exemplary embodiments, the first operating condition may also be defined as a cold start condition, the second operating condition is a small load condition, the third operating condition is a medium load condition, and the fourth operating condition is a large load condition.

[0087] Further, in the second working condition, when the intake air temperature is less than or equal to 0°C, the length of the heating end 40 extending into the cylinder 1 is 20 mm, and the temperature of the glow plug 4 is 1400 K. When the intake air temperature is greater than 0°C and less than 30°C, the length of the heating end 40 extending into the cylinder 1 is 15 mm, and the temperature of the glow plug 4 is 1300 K. When the intake air temperature is greater than or equal to 30°C, the length of the heating end 40 extending into the cylinder 1 is 10 mm, and the temperature of the glow plug 4 is 1200 K.

[0088] In the third working condition, when the intake air temperature is less than or equal to 25°C, the length of the heating end 40 extending into the cylinder 1 is 15 mm, and the temperature of the glow plug 4 is 1100 K. When the intake air temperature is greater than 25°C, the length of the heating end 40 extending into the cylinder 1 is 10 mm, and the temperature of the glow plug 4 is 1000 K.

[0089] In the fourth working condition, when the intake air temperature is less than or equal to 20°C, the length of the heating end 40 extending into the cylinder 1 is 10 mm, and the temperature of the glow plug 4 is 900 K. When the intake air temperature is greater than 20°C, the methanol mixture in the combustion chamber can achieve stable compression ignition, and the glow plug 4 no longer performs auxiliary heating.

[0090] In such an embodiment, the length of the heating end 40 extending into the cylinder 1 decreases as the accelerator pedal opening increases. More specifically, under the same operating conditions, the length of the heating end 40 extending into the cylinder 1 decreases as the intake temperature increases, thereby avoiding pre-ignition and comprehensively improving engine efficiency and emissions.

[0091] It will be appreciated by those skilled in the art that the features described in the various embodiments of the present disclosure may be combined and / or combined in a variety of ways, even if such combinations or combinations are not explicitly described in the present disclosure. In particular, without departing from the spirit and teachings of the present disclosure, the features described in the various embodiments of the present disclosure may be combined and / or combined in a variety of ways. All of these combinations and / or combinations fall within the scope of the present disclosure.

[0092] The embodiments of the present disclosure are described above. However, these embodiments are only for illustrative purposes and are not intended to limit the scope of the present disclosure. Although the embodiments are described above, this does not mean that the measures in the various embodiments cannot be used in combination to advantage. Without departing from the scope of the present disclosure, those skilled in the art may make a variety of substitutions and modifications, which should all fall within the scope of the present disclosure.

Claims

1. A compression ignition methanol engine, comprising a cylinder (1) and a piston (11) located inside the cylinder (1), wherein a combustion chamber is defined between the cylinder (1) and the top of the piston (11), wherein: Also includes: An air intake portion (2) is disposed at the top of the cylinder (1) and is in communication with the combustion chamber, and is suitable for guiding external air into the combustion chamber; A fuel injector (3) is arranged at the top of the cylinder (1) and is suitable for injecting methanol fuel into the combustion chamber to form a mixed gas with air from the outside; A glow plug (4) is mounted on the top of the cylinder (1), the glow plug (4) having a heating end (40) extending into the combustion chamber to heat the mixed gas, the heating end (40) being configured to generate a displacement close to or away from the injector (3) in response to at least one of an engine speed, an accelerator pedal opening, and an intake air temperature.

2. The compression ignition methanol engine according to claim 1, characterized in that: The glow plug (4) comprises: A housing (41) having an open end (411) located in the positioning hole of the cylinder (1) and a closed end (412) opposite to the open end (411); A heating core (42) extends from the shell (41) through the open end (411) into the combustion chamber.

3. The compression ignition methanol engine according to claim 2, characterized in that: One end of the heating core (42) extending into the combustion chamber is configured as the heating end (40), and the other end of the heating core (42) is configured to approach or move away from the closed end (412) of the shell (41) along a first direction under the action of a magnetic force.

4. The compression ignition methanol engine according to claim 2, characterized in that: An accommodating cavity is formed inside the shell (41), and a fluid working medium is filled in the accommodating cavity. The heating core (42) is configured to move back and forth along a second direction perpendicular to the first direction in response to the squeezing of the fluid working medium.

5. The compression ignition methanol engine according to claim 4, characterized in that: The accommodating chamber comprises a first accommodating chamber (413) and a second accommodating chamber (414); the first accommodating chamber (413) and the second accommodating chamber (414) are separated by the heating core (42) and are connected via an oil storage tank (415).

6. The compression ignition methanol engine according to claim 1, characterized in that: It also includes an exhaust portion (5), which is arranged at the top of the cylinder (1) and is connected to the combustion chamber and is suitable for guiding exhaust gas to be discharged from the combustion chamber.

7. The compression ignition methanol engine according to claim 6, characterized in that: It also comprises a power supply device (6) suitable for supplying power to the glow plug (4).

8. The compression ignition methanol engine according to claim 7, characterized in that: The power supply device (6) comprises: an impeller (61), arranged in the exhaust portion (5) and configured to rotate under the drive of the exhaust gas; a generator (62), connected to the impeller (61), and adapted to convert kinetic energy output by the impeller (61) into electrical energy; A storage battery (63) is suitable for storing the electric energy of the generator (62) and supplying power to the glow plug (4).

9. A compression ignition methanol engine control method, characterized in that: A compression ignition methanol engine according to any one of claims 1 to 8, comprising: Obtain engine speed and accelerator pedal opening information to determine engine operating conditions; According to the operating conditions, the distance between the axis of the glow plug (4) and the junction of the top of the cylinder (1) and the injector (3) is determined.

10. The control method according to claim 9, characterized in that: Also includes: The engine intake temperature is obtained, and according to the operating conditions and the intake temperature, the temperature of the glow plug (4) and the length of the heating end (40) extending into the cylinder (1) are adjusted.

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