Pre-combustion chamber heating system and engine cold start control method

Abstract

The invention provides a pre-combustion chamber heating system and an engine cold start control method. The pre-combustion chamber heating system comprises a shell, an oil sprayer, a spark plug, an induction coil and a multi-frequency inverter power supply. The shell is of a hollow structure, a pre-combustion chamber is formed in the shell, and the pre-combustion chamber is provided with a magnetic heat conversion layer. An outlet of the oil sprayer faces the pre-combustion chamber and is used for spraying fuel to the pre-combustion chamber. The sparking plug is used for igniting mixed gas in the pre-combustion chamber. And the induction coil is a conductive coil which is annularly distributed on the periphery of the shell. The multi-frequency inverter power supply is electrically connected with the induction coil and used for driving the induction coil to generate electromagnetic energy and converting the electromagnetic energy into heat energy through the magnetic-thermal conversion layer.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of internal combustion engines, and particularly relates to a pre-chamber heating system and an engine cold start control method. BACKGROUND

[0002] Methanol fuel is considered as an important direction for low-carbon transformation of internal combustion engines due to its clean and efficient characteristics. However, its high latent heat of vaporization and low vapor pressure result in poor cold start performance, which is manifested as difficult starting, unstable combustion and a sharp increase in hydrocarbon emissions. Traditional solutions use an electric heating plug or intake preheating, but there are problems such as response lag, high energy consumption and uneven temperature field distribution, which are difficult to meet the demand for rapid and reliable starting in low-temperature environments. The pre-chamber technology can improve combustion efficiency by igniting the main combustion chamber mixture with a high-temperature jet, but the insufficient temperature in the pre-chamber during the cold start stage makes it difficult to prepare the mixture, limiting the full play of its advantages. Existing pre-chamber heating technologies mostly rely on contact resistance heating, which has defects such as large thermal inertia, low temperature control precision and difficulty in zonal control, and cannot adapt to the differentiated temperature range requirements of different fuels. SUMMARY

[0003] To solve the above and other aspects of at least one technical problem in the prior art, embodiments of the present disclosure provide a pre-chamber heating system, which includes a shell, an oil injector, a spark plug, an induction coil and a multi-frequency inverter power supply. The shell has a hollow structure, a pre-chamber is formed in the shell, and the pre-chamber is provided with a magnetic heat conversion layer. The outlet of the oil injector faces the pre-chamber and is used to inject fuel into the pre-chamber. The spark plug is used to ignite the mixture in the pre-chamber. The induction coil is a conductive coil wrapped around the outer periphery of the shell. The multi-frequency inverter power supply is electrically connected to the induction coil and is used to drive the induction coil to generate electromagnetic energy, which is converted into heat energy by the magnetic heat conversion layer.

[0004] Optionally, the pre-chamber heating system further includes a control unit. The control unit is electrically connected to the temperature sensor in the shell, the oil injector, the spark plug and the multi-frequency inverter power supply, respectively. The control unit is used to measure the temperature of the shell.

[0005] Optionally, the working frequency of the multi-frequency inverter power supply is continuously adjustable in the range of 0-60 kHz.

[0006] Optionally, at least one jet hole is formed in the end of the shell away from the oil injector.

[0007] Optionally, the shell is made of a magnetically conductive alloy base, and the inner wall of the shell is provided with a ferrite composite coating to form the magnetic heat conversion layer.

[0008] Optionally, the thickness of the ferrite composite coating is in the range of 0.2-0.5 mm.

[0009] Optionally, the induction coil includes an independent water-cooled copper coil.

[0010] Embodiments of the present disclosure also provide an engine cold start control method applied to an engine comprising a pre-chamber heating system, wherein a housing is mounted to a cylinder head of the engine. The engine further comprises a cylinder body. The engine cold start control method comprises: when a temperature of the housing is lower than a first preset temperature, a control unit controls a multi-frequency inverter power supply to output a current of a first frequency; when the temperature of the housing is equal to or higher than the first preset temperature and lower than a second preset temperature, the control unit controls the multi-frequency inverter power supply to output a current of a second frequency; when the temperature of the housing is equal to or higher than the second preset temperature and lower than a third preset temperature, the control unit controls the multi-frequency inverter power supply to output a current of a third frequency. The second frequency is higher than the first frequency, and the third frequency is higher than the second frequency.

[0011] Optionally, the engine cold start control method further comprises: when the temperature of the housing is equal to or higher than the third preset temperature, the control unit further controls a spark plug to ignite.

[0012] Optionally, the engine cold start control method further comprises: when an engine idling is stable, the control unit further controls the multi-frequency inverter power supply to output a current of a fourth frequency. The fourth frequency is lower than the first frequency.

[0013] According to the precombustion chamber heating system provided by the present disclosure, electromagnetic energy is generated by driving an induction coil by a multi-frequency inverter power supply, and the electromagnetic energy is directly converted into heat energy in a magnetic heat conversion layer to provide a stable heating source for the precombustion chamber. In combination with the fuel injection device, methanol and other fuels are injected into the precombustion chamber, so that the methanol and other fuels in the precombustion chamber are smoothly atomized and form ignitable mixture gas. Then, the spark plug is ignited to promote the full combustion of the mixture gas, and a high-temperature jet flow that ignites the mixture gas in the main combustion chamber is formed, thereby helping to solve the problems of cold start difficulty, unstable combustion, and rapid increase of hydrocarbon emissions caused by high latent heat of vaporization and low vapor pressure of methanol and other fuels in the precombustion chamber and the main combustion chamber. Specifically, during the precombustion chamber heating process: first, electromagnetic induction heating does not require an intermediate heat conduction link, which helps to solve the response lag problem of the traditional preheating scheme. The induction coil arranged in the ring structure uniformly heats the magnetic heat conversion layer, which improves the problem of uneven temperature field distribution. The multi-frequency inverter power supply can output current as needed to reduce energy consumption. Second, the magnetic heat conversion layer can continuously provide heat energy, which helps to ensure that the temperature of the precombustion chamber meets the requirements of mixture gas preparation and helps to solve the problem of insufficient temperature of the precombustion chamber during the cold start stage. Third, electromagnetic direct heating has no conduction delay, which reduces the thermal inertia of the existing contact resistance heating. The ring-shaped coil supports uniform or zoned heating, which helps to overcome the defect that the precombustion chamber is difficult to control in different zones. The multi-frequency inverter power supply can respond to the differentiated temperature range requirements of different fuels. According to the engine cold start control method provided by the present disclosure, the control unit adjusts the output frequency of the multi-frequency inverter power supply in stages according to the temperature of the shell, that is, when the temperature is lower than the first preset temperature, the first frequency is output, when the temperature is between the first and second preset temperatures, the second higher frequency is output, and when the temperature is between the second and third preset temperatures, the third higher frequency is output. This strategy further optimizes the temperature control accuracy and avoids local overheating caused by single-frequency heating. At the same time, by increasing the frequency with the temperature, it is helpful to ensure that the precombustion chamber reaches the temperature required for ignition in the shortest time. This not only makes up for the low temperature control accuracy of existing heating technologies, but also improves the cold start efficiency, which helps to meet the demand for fast and reliable start-up in low-temperature environments. BRIEF DESCRIPTION OF DRAWINGS

[0014] The above and other objects, features and advantages of the present disclosure will become more apparent from the following description of embodiments of the present disclosure taken in conjunction with the accompanying drawings, in which:

[0015] Figure 1 The structure of the precombustion chamber heating system according to the embodiment of the present disclosure is schematically shown.

[0016] In the drawings, the meanings of the reference signs are as follows:

[0017] 1 - shell; 2 - fuel injection device; 3 - spark plug; 4 - induction coil; 5 - multi-frequency inverter power supply; 6 - control unit. DETAILED DESCRIPTION

[0018] In order to make the objects, technical solutions and advantages of the present disclosure clearer, the following further describes the present disclosure in detail with reference to specific embodiments and with reference to the drawings.

[0019] The terminology used herein is for the purpose of describing specific embodiments only and is not intended to be limiting of the present disclosure. As used herein, the term "includes" and tautological expressions thereof, such as "including," "includes," "include," "contains," "containing," and so on, mean the presence of stated features, steps, operations, elements, and / or components but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0020] All terms used herein, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning that is consistent with the context of the specification, and should not be interpreted in an idealized or overly formal manner.

[0021] In the case of using expressions similar to "at least one of A, B, and C, etc.", it should generally be interpreted to include any of them alone, any combination of two or more of them, etc. In the case of using expressions similar to "at least one of A, B, or C, etc.", it should generally be interpreted to include any of them alone, any combination of two or more of them, etc.

[0022] It is also to be noted that the directional terms mentioned in the embodiments, such as "upper", "lower", "front", "back", "left", "right", etc., are only the directions of the drawings and are not intended to limit the protection scope of the present disclosure. Throughout the drawings, the same elements are represented by the same or similar reference numerals. When the conventional structures or configurations may cause confusion in understanding the present disclosure, the conventional structures or configurations will be omitted.

[0023] Figure 1 The structure of the precombustion chamber heating system according to the embodiments of the present disclosure is schematically shown.

[0024] As Figure 1As shown, the present disclosure provides a pre-chamber heating system, which comprises a shell 1, an oil injector 2, a spark plug 3, an induction coil 4 and a multi-frequency inverter power supply 5. The shell 1 is in a hollow structure, and a pre-chamber is formed in the shell 1, and the pre-chamber is provided with a magnetic heat conversion layer. The outlet of the oil injector 2 is directed to the pre-chamber for injecting fuel into the pre-chamber. The spark plug 3 is used to ignite the mixture in the pre-chamber. The induction coil 4 is a conductive coil wrapped around the outer periphery of the shell 1. The multi-frequency inverter power supply 5 is electrically connected with the induction coil 4 for driving the induction coil 4 to generate electromagnetic energy, which is converted into heat energy through the magnetic heat conversion layer.

[0025] Specifically, the magnetic heat conversion layer includes but is not limited to being formed by laser cladding on the inner wall of the shell 1. The fuel includes but is not limited to methanol and other fuels. The oil injector 2 is installed on the upper part of the shell 1 and includes but is not limited to being provided as a high-pressure electromagnetic type. The fuel is atomized by the oil injector 2, and the fuel is mixed with the air in the pre-chamber to form a combustible mixture. The spark plug 3 is installed on the upper part of the shell 1 and is arranged in a spaced-apart manner with the oil injector 2, and includes but is not limited to being provided as an iridium gold electrode type. The mixture is ignited by the spark plug 3, and the high-temperature and high-pressure gas generated by the combustion is injected into the main combustion chamber in the form of a high-speed jet from the pre-chamber, thereby achieving the ignition of the mixture in the main combustion chamber.

[0026] The number of turns of the induction coil 4 wrapped around the outer periphery of the shell 1 includes but is not limited to 40-80 turns. The mode of electrical connection between the multi-frequency inverter power supply 5 and the induction coil 4 includes but is not limited to being connected through a high-temperature-resistant cable connected to the output end. The process in which the multi-frequency inverter power supply 5 drives the induction coil 4 to generate electromagnetic energy and converts it into heat energy through the magnetic heat conversion layer is as follows: when the multi-frequency inverter power supply 5 outputs an alternating current, an alternating electromagnetic field consistent with the frequency of the current is generated around the induction coil 4, the electromagnetic field passes through the shell 1 and acts on the magnetic heat conversion layer, the magnetic heat conversion layer generates eddy current due to electromagnetic induction (the size of the eddy current is positively correlated with the frequency of the electromagnetic field), the eddy current generates Joule heat inside the magnetic heat conversion layer due to material resistance, the temperature of the magnetic heat conversion layer is raised, and the air in the pre-chamber and the inner wall of the shell 1 are directly heated through heat conduction.

[0027] In this implementation, the multi-frequency inverter power supply 5 drives the induction coil 4 to generate electromagnetic energy. The electromagnetic energy is directly converted into heat energy in the magnetocaloric conversion layer, providing a stable heating source for the pre-combustion chamber. In conjunction with the fuel injector 2, methanol and other fuels are injected into the pre-combustion chamber, so that the methanol and other fuels in the pre-combustion chamber are smoothly atomized and form an ignitable mixture. Then, the spark plug 3 ignites and promotes the complete combustion of this mixture, forming a high-temperature jet that ignites the mixture in the main combustion chamber. This helps to solve the problems of cold start difficulty, unstable combustion, and surge in hydrocarbon emissions caused by the high latent heat of vaporization and low vapor pressure of methanol and other fuels in the pre-combustion chamber and the main combustion chamber. Specifically, during the pre-combustion chamber heating process: First, electromagnetic induction heating eliminates the need for intermediate heat conduction, which helps solve the response lag problem of traditional preheating schemes. The ring-shaped induction coils 4 ensure uniform heating of the magnetocaloric conversion layer, improving the problem of uneven temperature field distribution. The multi-frequency inverter power supply 5 can output current on demand to reduce energy consumption. Second, the magnetocaloric conversion layer can continuously provide heat energy, which helps ensure that the pre-combustion chamber temperature meets the requirements for mixture preparation and helps solve the problem of insufficient pre-combustion chamber temperature during the cold start stage. Third, electromagnetic direct heating has no conduction delay, reducing the thermal inertia of existing contact resistance heating. The ring coils support uniform or zoned heating, which helps overcome the defect of difficult zoned control in the pre-combustion chamber. The multi-frequency inverter power supply 5 can respond to the differentiated temperature range requirements of different fuels.

[0028] According to some embodiments of this disclosure, the pre-combustion chamber heating system further includes a control unit 6. The control unit 6 is electrically connected to a temperature sensor, an injector 2, a spark plug 3, and a multi-frequency inverter power supply 5 within the housing 1. The control unit 6 is used to measure the temperature of the housing 1.

[0029] Specifically, the control unit 6 includes an integrated temperature acquisition module (such as a thermocouple or infrared sensor), a signal processing module, and an execution command output module. The control unit 6 is also used to start the fuel injector 2 to begin injection, start the spark plug 3 to begin ignition, and adjust the output frequency and power of the multi-frequency inverter power supply 5. The control unit 6 is electrically connected to the temperature sensor, fuel injector 2, spark plug 3, and multi-frequency inverter power supply 5 within the housing 1, respectively, in ways including but not limited to connecting via high-temperature resistant cables to the output terminals. The control unit 6 receives the temperature signal from the housing 1 and sends electrical signal commands to the fuel injector 2, spark plug 3, and multi-frequency inverter power supply 5, including but not limited to adjusting the output frequency and power of the multi-frequency inverter power supply 5 based on a fuzzy PID algorithm. Furthermore, the sampling frequency of the temperature data of the housing 1 by the control unit 6 is, but is not limited to, set to 10-100Hz.

[0030] In this implementation, the control unit 6 is electrically connected to the fuel injector 2, spark plug 3, and multi-frequency inverter 5, and the temperature measurement function of the housing 1 enables real-time temperature monitoring during the heating process in the pre-combustion chamber. This facilitates dynamic adjustment of the heating process in the pre-combustion chamber through frequency switching and ignition start-up, helping the fuel in the pre-combustion chamber to be fully atomized, mixed evenly with air, and fully combusted. The temperature of the housing 1 provides real-time data support for switching the output frequency of the multi-frequency inverter 5, reducing the lag in the heating process adjustment and improving the efficiency and reliability of the pre-combustion chamber heating system during use.

[0031] According to some embodiments of this disclosure, the operating frequency of the multi-frequency inverter 5 is configured to be continuously adjustable in the range of 0-60kHz.

[0032] Specifically, continuously adjustable operating frequency means that the AC frequency output by the multi-frequency inverter 5 can be smoothly varied between 0 and 60 kHz, including but not limited to achieving this through the inclusion of a high-frequency inverter circuit (such as pulse width modulation using an IGBT module) within the multi-frequency inverter 5. Low frequencies (e.g., 0-20 kHz) are suitable for maintaining the temperature of the pre-combustion chamber, while high frequencies (e.g., 40-60 kHz) are suitable for rapidly heating the pre-combustion chamber. Furthermore, during the adjustment of the operating frequency of the multi-frequency inverter 5, the current must be kept stable to avoid impacting the induction coil 4 and the magnetocaloric conversion layer.

[0033] In this implementation, by configuring a continuously adjustable operating frequency, the multi-frequency inverter power supply 5 can match a suitable operating frequency according to different temperature conditions of the pre-combustion chamber or engine (such as cold start, idling speed), taking into account both heating efficiency and energy utilization.

[0034] According to some embodiments of this disclosure, at least one jet hole is provided at the end of the housing 1 that is away from the injector 2.

[0035] Specifically, the end of the housing 1 that is furthest from the injector 2 is the outlet end of the pre-combustion chamber (the side closest to the main combustion chamber). The diameter of the jet orifice is, but is not limited to, set to 3-8mm (adjusted according to engine power), serving as a channel for the high-temperature, high-pressure gas in the pre-combustion chamber to be injected into the main combustion chamber.

[0036] In this implementation, by setting jet holes, the high-temperature and high-pressure gas from the pre-combustion chamber is injected into the main combustion chamber to ignite the gas mixture in the main combustion chamber.

[0037] According to some embodiments of this disclosure, the housing 1 is made of a magnetically conductive alloy substrate, and the inner wall of the housing 1 is provided with a ferrite composite coating to form a magnetocaloric conversion layer.

[0038] Specifically, the magnetically conductive alloy substrate refers to an alloy material with high magnetic permeability (such as iron-nickel alloy or silicon steel sheet), which enhances the electromagnetic field strength generated by the induction coil 4. The ferrite composite coating is composed of ferrite particles (such as Mn-Zn ferrite) and a high-temperature resistant binder (such as ceramic binder), which covers the inner wall of the shell 1 with uniform thickness.

[0039] In this implementation, the magnetic alloy substrate is used to enhance the magnetic field, while the ferrite composite coating can induce eddy currents based on the high-frequency electromagnetic field and convert them into heat energy. Through the synergistic effect of the magnetic alloy substrate and the ferrite composite coating, the conversion rate of electromagnetic energy to heat energy is improved, and energy loss is reduced.

[0040] According to some embodiments of this disclosure, the thickness of the ferrite composite coating is in the range of 0.2-0.5 mm.

[0041] Specifically, if the ferrite composite coating is too thin, the eddy current path in the magnetocaloric conversion layer will be short, resulting in insufficient heat generation. If the ferrite composite coating is too thick, the heat inside the magnetocaloric conversion layer will be difficult to conduct to the pre-combustion chamber, and the weight of the shell will increase. In actual production, the thickness of the ferrite composite coating is controlled using a laser thickness gauge. For example, during the application of the ferrite composite coating, a detection point is set every 10 mm to monitor the thickness in real time. If the thickness in a certain area exceeds the range, it is corrected by local re-spraying or grinding. In addition, when the ferrite composite coating is finally applied, ultrasonic testing is used to detect whether there are air bubbles inside the coating to avoid affecting thermal conductivity.

[0042] In this implementation, by controlling the thickness of the ferrite composite coating within a suitable range, it is beneficial to ensure that the magnetocaloric conversion layer generates sufficient eddy currents and heat, and at the same time, to achieve efficient heat transfer from the magnetocaloric conversion layer to the main combustion chamber, thereby increasing the pre-combustion chamber heating rate. Furthermore, by controlling the thickness and quality of the ferrite composite coating, the performance consistency of the coating is improved, helping to avoid uneven heating inside the pre-combustion chamber caused by localized thickness abnormalities, and enhancing the reliability of the pre-combustion chamber heating system.

[0043] According to some embodiments of this disclosure, the induction coil 4 includes an independent water-cooled copper coil.

[0044] Specifically, the independent water-cooled type refers to the induction coil 4 having an independent cooling water channel inside (such as a copper pipe embedded inside the induction coil 4). A water pump drives the cooling water circulation to remove the heat generated by the high-frequency current in the induction coil 4. Simultaneously, the induction coil 4 is made of copper, utilizing copper's high conductivity to reduce current loss. Furthermore, the induction coil 4 is, but is not limited to, made of multiple strands of enameled wire twisted together. The induction coil 4 is, but is not limited to, tightly wound around the outer periphery of the housing 1 (with a spacing of ≤0.5mm between adjacent induction coils 4) to enhance the magnetic field strength.

[0045] In this implementation, by setting up an independent water cooling system, overheating of the induction coil 4 can be avoided when it is operating at high frequency. At the same time, the use of copper material reduces resistance loss, thereby improving the energy utilization rate of the induction coil 4 and ensuring its long-term stable operation.

[0046] Embodiments of this disclosure also provide an engine cold start control method applied to an engine including a pre-combustion chamber heating system, wherein a housing 1 is mounted on the engine cylinder head. The engine also includes a cylinder block. The engine cold start control method includes: when the temperature of the housing 1 is lower than a first preset temperature, a control unit 6 causes a multi-frequency inverter 5 to output a current of a first frequency. When the temperature of the housing 1 is equal to or higher than the first preset temperature and lower than a second preset temperature, the control unit 6 causes the multi-frequency inverter 5 to output a current of a second frequency. When the temperature of the housing 1 is equal to or higher than the second preset temperature and lower than a third preset temperature, the control unit 6 causes the multi-frequency inverter 5 to output a current of a third frequency. The second frequency is higher than the first frequency, and the third frequency is higher than the second frequency.

[0047] According to some embodiments of this disclosure, the engine cold start control method further includes: when the temperature of the housing 1 is equal to or higher than a third preset temperature, the control unit 6 also ignites the spark plug 3.

[0048] Specifically, this includes, but is not limited to, fixing the housing 1 to the pre-set mounting holes in the cylinder head using bolts or interference fits. The cylinder block is, but is not limited to, made of cast iron or aluminum alloy. Inside the cylinder block is the piston-driven cylinder, with the piston top sealing against the cylinder head to form the main combustion chamber. The main combustion chamber is the engine's primary combustion space. When the high-temperature, high-pressure combustion gases from the pre-combustion chamber are injected into the main combustion chamber, they ignite a large amount of the air-fuel mixture, driving the piston to perform work. Furthermore, a high-temperature resistant sealing assembly is installed between the housing 1 and the cylinder head to prevent leakage of high-temperature, high-pressure combustion gases.

[0049] Engine cold start refers to the starting process of an engine when the ambient temperature is below -5°C or after being shut down for more than 8 hours. The preset temperature is the temperature of the housing 1 measured by the control unit 6. The first preset temperature includes, but is not limited to, 0°C; the second preset temperature includes, but is not limited to, 60°C; and the third preset temperature includes, but is not limited to, the ignition critical temperature within the housing 1. Furthermore, the first frequency includes, but is not limited to, 20kHz; the second frequency includes, but is not limited to, 40kHz; and the third frequency includes, but is not limited to, 60kHz.

[0050] In this implementation, the control unit 6 adjusts the output frequency of the multi-frequency inverter power supply 5 in stages according to the temperature of the housing 1. That is, when the temperature is lower than the first preset temperature, the first frequency is output; when the temperature is between the first and second preset temperatures, a higher second frequency is output; and when the temperature is between the second and third preset temperatures, a higher third frequency is output. This further optimizes the temperature control accuracy and avoids local overheating caused by heating with a single frequency. At the same time, by using a strategy of increasing the frequency with temperature, it is beneficial to ensure that the pre-combustion chamber reaches the temperature required for ignition in the shortest possible time. This not only makes up for the lack of low temperature control accuracy in existing heating technologies, but also improves cold start efficiency, which is conducive to meeting the needs of rapid and reliable start-up in low-temperature environments.

[0051] According to some embodiments of this disclosure, the engine cold start control method further includes: when the engine idle speed is stable, the control unit 6 further causes the multi-frequency inverter 5 to output a current of a fourth frequency. The fourth frequency is lower than the first frequency.

[0052] Specifically, stable engine idling speed refers to the engine speed being maintained within the range of 800±50 rpm, with fluctuations lasting less than 30 seconds. The fourth frequency includes, but is not limited to, 10 kHz.

[0053] In this implementation, by reducing the output frequency of the multi-frequency inverter power supply 5 when the engine is idling steadily, the continued heating in the pre-combustion chamber is reduced. At this time, the pre-combustion chamber can rely on residual heat to achieve heat preservation, thereby reducing the energy consumption of the engine and improving the fuel economy during the engine idling steady stage.

[0054] The embodiments of this disclosure have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of this disclosure. Although various embodiments have been described above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. The scope of this disclosure is defined by the appended claims and their equivalents. Various substitutions and modifications can be made by those skilled in the art without departing from the scope of this disclosure, and all such substitutions and modifications should fall within the scope of this disclosure.

Claims

1. A pre-combustion chamber heating system, characterized in that, include: The shell (1) has a hollow structure, and a pre-combustion chamber is formed inside the shell (1). The pre-combustion chamber is provided with a magnetocaloric conversion layer. The injector (2) has its outlet facing the pre-combustion chamber and is used to inject fuel into the pre-combustion chamber; Spark plug (3) is used to ignite the mixture in the pre-combustion chamber; Induction coil (4), a conductive coil arranged around the outer periphery of the housing (1); The multi-frequency inverter power supply (5) is electrically connected to the induction coil (4) and is used to drive the induction coil (4) to generate electromagnetic energy, which is then converted into thermal energy through the magnetocaloric conversion layer.

2. The pre-combustion chamber heating system according to claim 1, characterized in that, Also includes: The control unit (6) is electrically connected to the temperature sensor, the fuel injector (2), the spark plug (3), and the multi-frequency inverter power supply (5) inside the housing (1); The control unit (6) is used to measure the temperature of the housing (1).

3. The pre-combustion chamber heating system according to claim 1, characterized in that, The operating frequency of the multi-frequency inverter (5) is configured to be continuously adjustable in the range of 0-60kHz.

4. The pre-combustion chamber heating system according to claim 1, characterized in that, The housing (1) has at least one jet hole at the end that is away from the injector (2).

5. The pre-combustion chamber heating system according to claim 1, characterized in that, The housing (1) is made of a magnetically conductive alloy substrate, and the inner wall of the housing (1) is provided with a ferrite composite coating to form the magnetocaloric conversion layer.

6. The pre-combustion chamber heating system according to claim 5, characterized in that, The thickness of the ferrite composite coating is in the range of 0.2-0.5 mm.

7. The pre-combustion chamber heating system according to claim 1, characterized in that, The induction coil (4) includes an independent water-cooled copper coil.

8. A method for controlling engine cold start, characterized in that, An engine comprising a pre-combustion chamber heating system as described in any one of claims 1-7, wherein the housing (1) is mounted on the cylinder head of the engine; the engine further comprises a cylinder block; The engine cold start control method includes: When the temperature of the housing (1) is lower than the first preset temperature, the control unit (6) causes the multi-frequency inverter power supply (5) to output a current of the first frequency; When the temperature of the housing (1) is equal to or higher than the first preset temperature and lower than the second preset temperature, the control unit (6) causes the multi-frequency inverter power supply (5) to output a current of the second frequency; When the temperature of the housing (1) is equal to or higher than the second preset temperature and lower than the third preset temperature, the control unit (6) causes the multi-frequency inverter power supply (5) to output a current of the third frequency; Wherein, the second frequency is higher than the first frequency, and the third frequency is higher than the second frequency.

9. The engine cold start control method according to claim 8, characterized in that, Also includes: When the temperature of the housing (1) is equal to or higher than the third preset temperature, the control unit (6) also ignites the spark plug (3).

10. The engine cold start control method according to claim 8, characterized in that, Also includes: When the engine idles at a stable speed, the control unit (6) also causes the multi-frequency inverter power supply (5) to output a current of a fourth frequency; The fourth frequency is lower than the first frequency.

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