Variable combustion jet piloted free piston power generation system and control method

Abstract

The application provides a variable combustion jet piloted free piston power generation system and a control method, relates to the technical field of internal combustion generators, and comprises a linear motor, a connecting rod assembly, a jet piloted free piston engine, a state acquisition system and a control system; the linear motor is connected with the jet piloted free piston engine through the connecting rod assembly; the jet piloted free piston engine comprises a cylinder body, a piston and a pre-chamber; a first fuel injector and a second fuel injector are respectively arranged on an air inlet pipeline and a main combustion chamber of the cylinder body; a third fuel injector is arranged in the pre-chamber; the running state of the jet piloted free piston power generation system is acquired through the state acquisition system, and the running state is transmitted to the control system; and the control system sends a control signal to control the first fuel injector, the second fuel injector and the third fuel injector. The application improves the combustion process in the cylinder of the system and enhances the adaptability of the system to low active fuel.

Description

Technical Field

[0001] The present invention relates to the technical field of internal combustion generators, and in particular to a variable combustion jet-ignited free piston power generation system and a control method thereof. Background Art

[0002] The free-piston internal combustion generator includes a free-piston engine and a linear motor. The piston of the free-piston engine is directly coupled to the linear motor rotor through a connecting rod, and electrical energy is directly output through the linear reciprocating motion of the piston. It has the advantages of simple structure, short energy transmission chain, high energy conversion efficiency and flexible and adjustable compression ratio. Due to its direct output of electrical energy, it can be used in new energy vehicle range extenders, island power generation, ship power generation, etc., and has broad application prospects.

[0003] The variable combustion jet-ignited free piston power generation system optimizes combustion efficiency, power output and power generation efficiency by precisely controlling the combustion process and piston movement. It can dynamically adjust the combustion method and injection strategy according to different system modes, and use jet ignition technology to improve flame propagation and isochoric combustion effects in the initial stage of combustion, which helps to further enhance the system adaptability and overall performance.

[0004] However, traditional free piston power generation systems usually adopt a two-stroke working mode during operation, which results in a long combustion duration, making it difficult to achieve fast and efficient combustion, and the overall combustion efficiency of the system is relatively low. Traditional free piston power generation systems have poor adaptability to low-activity fuels, making it difficult to fully burn in the system, reducing the energy conversion efficiency of the system. Summary of the Invention

[0005] In order to solve the technical problems that traditional free piston power generation systems usually adopt a two-stroke working mode during operation, resulting in a long combustion duration, difficulty in achieving fast and efficient combustion, and low overall combustion efficiency of the system, and traditional free piston power generation systems have poor adaptability to low-activity fuels, making it difficult to fully burn in the system, thereby reducing the energy conversion efficiency of the system, the present invention provides a variable combustion jet-ignited free piston power generation system and a control method.

[0006] The technical solutions provided by the embodiments of the present invention are as follows:

[0007] First aspect:

[0008] An embodiment of the present invention provides a variable combustion jet-ignited free piston power generation system, comprising: a linear motor, a connecting rod assembly, a jet-ignited free piston engine, a state acquisition system, and a control system;

[0009] The linear motor is connected to the jet-ignition free piston engine via a connecting rod assembly;

[0010] The jet piloted free piston engine comprises a cylinder body, a piston and a precombustion chamber;

[0011] The intake pipeline and the main combustion chamber of the cylinder body are respectively provided with a first fuel injector and a second fuel injector;

[0012] The precombustion chamber is provided with a third fuel injector;

[0013] The running state of the jet piloted free piston engine system is collected by a state collection system, and the running state is transmitted to a control system, and a control signal is sent by the control system to control the first fuel injector, the second fuel injector and the third fuel injector.

[0014] The second aspect is:

[0015] The control method provided by the embodiment of the application is applied to the variable combustion jet piloted free piston engine system provided by the first aspect, and the method comprises the following steps:

[0016] S1: collecting the running state of the jet piloted free piston engine system by a state collection system;

[0017] S2: according to the running state, the power generation capacity of the jet piloted free piston engine system is optimized by the control system in different system modes;

[0018] The system modes include a normal mode, a motion mode and an energy saving mode.

[0019] The technical scheme provided by the embodiment of the application has at least the following beneficial effects:

[0020] In the application, according to the running state of the jet piloted free piston engine system, a control signal is sent by the control system to control the fuel injector, the precombustion chamber jet mode and the main combustion chamber combustion mode are flexibly switched, the combustion efficiency is improved, the system cylinder combustion process is improved, so that the system can better adapt to different working modes, effectively expand the fuel applicability of the free piston internal combustion generator, and promote the use and development of the free piston internal combustion generator technology. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical scheme in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0022] Figure 1 The structure schematic diagram of the variable combustion jet piloted free piston engine system provided by the embodiment of the application is shown in the figure;

[0023] Figure 2 A premixed combustion structure schematic diagram of a variable combustion jet piloted free piston power generation system provided by an embodiment of the present application;

[0024] Figure 3 A diffusion combustion structure schematic diagram of a variable combustion jet piloted free piston power generation system provided by an embodiment of the present application;

[0025] Figure 4 A flow chart of a control method provided by an embodiment of the present application.

[0026] [Reference signs]

[0027] 1, mover; 2, stator; 3, motor housing; 4, linear motor displacement sensor; 5, motor end spring seat; 6, spring; 7, connecting rod; 8, piston end spring seat; 9, premix fuel injector; 10, intake pipeline; 11, cylinder body; 12, piston; 13, piston pin; 14, piston ring; 15, diffusion fuel injector; 16, in-cylinder pressure sensor; 17, pre-chamber fuel injector; 18, pre-chamber; 19, spark plug; 20, cylinder wall temperature sensor; 21, oxygen sensor; 22, exhaust pipeline.

[0028] As shown in the drawings, in order to clearly realize the structure of the embodiments of the present application, specific structures and devices are marked in the drawings, but this is only for the need of illustration, and is not intended to limit the present application in the specific structures, devices and environments, and those skilled in the art can adjust or modify these devices and environments according to specific needs. DETAILED DESCRIPTION

[0029] The technical solutions in the present application will be described below in combination with the drawings. It should be noted that, in order to make the embodiments more detailed, the following embodiments are the best and preferred embodiments, and other alternative ways can also be used by those skilled in the art to implement some known technologies; and the drawings are only used to more specifically describe the embodiments, and are not intended to specifically limit the present application.

[0030] It should be noted that the embodiments indicated by "one embodiment", "embodiment", "exemplary embodiment", "some embodiments" and the like in the specification can include specific features, structures or characteristics, but not necessarily every embodiment includes the specific features, structures or characteristics. In addition, when a specific feature, structure or characteristic is described in combination with an embodiment, it should be within the knowledge of those skilled in the art to realize this feature, structure or characteristic in combination with other embodiments (whether or not explicitly described).

[0031] In general, terms can be understood, at least in part, from their use in context. For example, depending at least in part on the context, the term "one or more" as used herein can be used to describe any feature, structure, or characteristic in the singular sense, or can be used to describe a combination of features, structures, or characteristics in the plural sense. Additionally, the term "based on" can be understood as not necessarily intended to convey an exclusive set of factors, but can instead, depending at least in part on the context, allow for the presence of other factors that are not necessarily explicitly described.

[0032] It will be understood that the meanings of “on,” “over,” and “above” in the present invention should be interpreted in the broadest manner, so that “on” means not only “directly on” something but also includes the meaning of being “on” something with intervening features or layers, and “on” or “above” means not only “on” or “above” something but also includes the meaning of being “on” or “above” something with no intervening features or layers.

[0033] Additionally, spatially relative terms such as "below," "beneath," "lower," "above," and "upper" may be used herein for descriptive convenience to describe the relationship of one element or feature to another element or features, as illustrated in the accompanying drawings. Spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the accompanying drawings. The device may be oriented in other ways, and the spatially relative descriptors used herein should be similarly interpreted accordingly.

[0034] Reference Manual Figure 1 , showing a schematic diagram of the mechanism of a variable combustion jet-ignited free piston power generation system provided by an embodiment of the present invention.

[0035] Reference Manual Figure 2 , showing a schematic diagram of the premixed combustion structure of a variable combustion jet-ignited free piston power generation system provided by an embodiment of the present invention.

[0036] like Figure 2 The fuel is sprayed into the cylinder through the injector located in the intake pipe and is fully mixed with the incoming air to form an oil-gas mixture. In the premixed combustion mode, the fuel achieves a high degree of atomization and mixing before entering the combustion chamber, which is beneficial to the uniformity and stability of the combustion process. The spark plug is located in the precombustion chamber and is responsible for igniting the premixed gas. The flame then propagates to the main combustion chamber to achieve an efficient combustion process. This structure can optimize combustion efficiency and reduce energy loss and emissions caused by incomplete combustion.

[0037] Reference Manual Figure 3Fig. 1 shows a schematic diagram of a diffusion combustion structure of a variable combustion jet piloted free-piston power generation system according to an embodiment of the present application.

[0038] As shown in Fig. 1, the variable combustion jet piloted free-piston power generation system according to an embodiment of the present application comprises a linear motor, a connecting rod assembly, a jet piloted free-piston engine, a state acquisition system and a control system. Figure 3 In the diffusion combustion mode, the fuel is directly injected into the main combustion chamber through the fuel injector, the fuel and air are gradually mixed during the combustion process, and the flame is ignited in the pre-chamber and spreads to the main combustion chamber, combines with the newly injected fuel and starts diffusion combustion.

[0039] The variable combustion jet piloted free-piston power generation system according to an embodiment of the present application comprises a linear motor, a connecting rod assembly, a jet piloted free-piston engine, a state acquisition system and a control system.

[0040] The linear motor is connected to the jet piloted free-piston engine through the connecting rod assembly.

[0041] The jet piloted free-piston engine comprises a cylinder body 11, a piston 12 and a pre-chamber 13.

[0042] The intake pipe and the main combustion chamber of the cylinder body 11 are respectively provided with a first fuel injector 9 and a second fuel injector 15.

[0043] A third fuel injector 17 is installed in the pre-chamber 18.

[0044] The state acquisition system acquires the operating state of the jet piloted free-piston power generation system and transmits the operating state to the control system, and the control system sends control signals to control the first fuel injector 9, the second fuel injector 15 and the third fuel injector 17.

[0045] It should be noted that the system operating state such as pressure, temperature and oxygen concentration is monitored in real time by the state acquisition system, and the working state of each fuel injector is accurately adjusted by the control system to realize flexible switching between different combustion modes.

[0046] In a possible implementation, the linear motor comprises a mover 1, a stator 2 and a motor housing 3.

[0047] The linear motor is internally provided with permanent magnets to generate a magnetic field to drive the mover 1 to move linearly.

[0048] It should be noted that the linear motor generates a magnetic field through the stator, directly drives the mover to move linearly, and eliminates the rotation-linear conversion mechanism of the traditional motor. This design has simple structure, fast response, small energy loss, can improve the transmission efficiency and accuracy of the system, reduce mechanical wear and maintenance cost, and improve the overall reliability of the system.

[0049] In a possible implementation, the first fuel injector 9 and the second fuel injector 15 are used to adapt to different combustion modes of the jet ignition free piston internal combustion generator.

[0050] The third fuel injector 17 is used to switch the jet mode.

[0051] The spark plug 19 is installed inside the pre-chamber 13, and the spark plug 19 is used to ignite the mixture in the pre-chamber.

[0052] It should be noted that the first fuel injector and the second fuel injector adapt to different combustion modes, the third fuel injector switches the jet mode, and the spark plug in the pre-chamber ignites the mixture, which can flexibly control the combustion process according to the working condition requirements, and optimize the combustion efficiency and stability.

[0053] In a possible implementation, the connecting rod assembly includes a motor end spring seat 5, a spring 6, a connecting rod 7, and a piston end spring seat 8.

[0054] The spring 6 is arranged between the motor end spring seat 5 and the piston end spring seat 8, and is sleeved on the connecting rod 7.

[0055] The two ends of the connecting rod 7 are connected to the mover main shaft 1 and the piston 12 through bolts, respectively.

[0056] It should be noted that the connecting rod assembly realizes efficient connection of the linear motor and the piston through the motor end spring seat, the spring, and the piston end spring seat. The spring effectively buffers the impact force during the movement of the mover and the piston, reduces mechanical wear, prolongs the service life of the system, and ensures the reliability and stability of the system.

[0057] In a possible implementation, the state acquisition system includes a linear motor displacement sensor 4, an in-cylinder pressure sensor 16, a cylinder wall temperature sensor 20, and an oxygen sensor 21.

[0058] The linear motor displacement sensor 4 is installed on the motor housing 3 and is used to record the position information of the jet ignition free piston generator system during the working process.

[0059] The in-cylinder pressure sensor 16 is installed at the top end area of the cylinder cover of the main combustion chamber of the cylinder body 11, and is used to record the gas pressure change in the main combustion chamber of the jet ignition free piston generator system during the working process.

[0060] The cylinder wall temperature sensor 20 is installed in the middle region of the cylinder cover to record the cylinder wall temperature change of the jet ignition free piston power generation system during the working process.

[0061] The oxygen sensor 21 is installed in the exhaust pipeline to record the oxygen concentration of the exhaust gas generated by the jet ignition free piston power generation system during the working process.

[0062] It should be noted that the state acquisition system acquires key data of the system in real time through the linear motor displacement sensor, the in-cylinder pressure sensor, the cylinder wall temperature sensor and the oxygen sensor, which provides accurate basis for the combustion process monitoring and adjustment of the system, optimizes the combustion efficiency, realizes flexible control in multiple modes, and timely discovers abnormal conditions to ensure efficient and stable operation of the system under different working conditions, and improves the overall performance and reliability of the system.

[0063] In a possible implementation, the control system includes a host computer and a control ECU.

[0064] The control ECU is connected with the first fuel injector 9, the second fuel injector 15, the third fuel injector 17, the spark plug 19, the state acquisition system and the motor controller through connection lines respectively.

[0065] The state acquisition system transmits the acquired data to the host computer, and the host computer analyzes the in-cylinder combustion process according to the acquisition data and transmits a control signal to the control ECU.

[0066] It should be noted that the control system cooperates with the control ECU through the host computer to realize closed-loop control of data acquisition, analysis and instruction execution, the state acquisition system provides real-time operation data, the host computer accurately analyzes the in-cylinder combustion process based on the data and sends a control signal to the ECU, so as to flexibly adjust the working state of the fuel injector, the spark plug and the motor controller, ensure accurate control of the system under different working conditions, improve the combustion efficiency, power output and economy, and at the same time, enhance the adaptability and stability of the system to meet the demand of multiple fuels and modes.

[0067] The technical scheme provided by the embodiment of the application has at least the following beneficial effects:

[0068] In the present application, according to the operating state of the jet ignition free piston power generation system, the control system sends a control signal to control the fuel injector, flexibly switches the pre-chamber jet mode and the main combustion chamber combustion mode, improves the combustion efficiency, and improves the in-cylinder combustion process of the system, so that the system can better adapt to different working modes, effectively expand the fuel applicability of the free piston internal combustion generator, and promote the use and development of the free piston internal combustion generator technology.

[0069] Reference is made to the accompanying drawings Figure 4Fig. 1 shows a flowchart of a control method according to the present application.

[0070] The present application also provides a control method applied to a variable combustion jet piloted free piston power generation system, which comprises the following steps:

[0071] S1: Collecting the operating state of the jet piloted free piston power generation system through a state acquisition system.

[0072] It should be noted that the state acquisition system can monitor the key operating parameters of the jet piloted free piston power generation system in real time, such as position information, in-cylinder pressure, cylinder wall temperature and tail gas oxygen concentration, to provide accurate data support for the combustion state, output power and operating efficiency of the system, so as to ensure that the control system can make a quick response and accurate adjustment, thereby optimizing the combustion process, improving the system performance and stability, and meeting the efficient operation demand under multiple working conditions.

[0073] S2: According to the operating state, using the control system to optimize the power generation capacity of the jet piloted free piston power generation system in different system modes.

[0074] The system mode includes a normal mode, a motion mode and an energy saving mode.

[0075] It should be noted that the control system flexibly switches different system modes according to the real-time collected operating state data, so as to meet the demand under different working conditions. In the normal mode, the system balances the power performance and economy, in the motion mode, the power output is improved, and in the energy saving mode, the combustion efficiency is optimized, the fuel consumption and emissions are reduced. This intelligent control effectively improves the adaptability, operating efficiency and stability of the system, and ensures that the power generation system realizes the best performance under multiple working conditions.

[0076] In actual operation, the host computer sends a start command to the control ECU, and the system is cold started under the dragging of the linear motor. When the in-cylinder pressure collected by the in-cylinder pressure sensor is greater than 8 bar, the required pressure for ignition is met. At this time, the type of fuel used is judged. When the fuel has high requirements on atomization characteristics, diesel, hydrogen and aviation kerosene are selected to be installed in the oil injector of the cylinder body, and when the fuel has general requirements on atomization characteristics, gasoline, natural gas and alcohol are selected to be installed in the oil injector of the intake pipe. Then the host computer sends a command to the spark plug to ignite, and the combustion system starts to work. When the system continuously and stably operates for 1 min, the linear motor is switched from the electric mode to the power generation mode.

[0077] In one possible implementation, when the system mode is the normal mode, the optimization of the power generation capacity of the jet piloted free piston power generation system specifically includes:

[0078] The gas pressure in the cylinder and the system position information of the jet ignition free piston generator system are detected by a cylinder pressure sensor and a linear motor displacement sensor respectively.

[0079] The system output power of the jet ignition free piston generator system is determined by the gas pressure and the system position information.

[0080] When the system output power is lower than the preset system output power, the third fuel injector is activated by the control system to switch the jet mode to the active jet mode, thereby optimizing the power generation capacity of the jet ignition free piston generator system and improving the power generation capacity of the jet ignition free piston generator system.

[0081] When the system output power is higher than the preset system output power, the jet ignition free piston generator system is stopped by the control system to avoid waste of the output power of the jet ignition free piston generator system.

[0082] Wherein, according to the cylinder gas pressure p, displacement information x, cylinder diameter D and the running stroke S of the free piston generator, the corresponding system work can be derived:

[0083] V = 0.25πD 2 (S-x)

[0084] W = ∫pVdt

[0085] Wherein, V represents the volume of the cylinder, D represents the diameter of the rigid body, S represents the running stroke of the free piston generator, x represents the displacement information, W represents the work of the free piston generator system, and p represents the cylinder gas pressure.

[0086] It should be noted that by monitoring the cylinder pressure and system position information in real time, the output power is accurately determined, the control system dynamically adjusts the power generation state, ensures that the system output power meets the demand, avoids energy waste, balances the power and economy, and improves the overall efficiency and stability of the system.

[0087] Specifically, when the system switches to the normal mode, the system needs to balance the power and economy at the same time, the cylinder gas pressure is detected by the cylinder pressure sensor, and the system position information is detected by the linear motor displacement sensor, so as to determine the system output power at this time, and compare the system output power with the design value, when the output power is lower than the design value, the upper computer sends an instruction to the control ECU at this time, so that the precombustion chamber fuel injector starts to work, which is used to improve the fuel concentration in the precombustion chamber, improve the initial state of flame propagation, improve the constant volume degree of combustion, and thereby improve the system work capacity; when the output power is higher than the design value, the upper computer sends an instruction to the control ECU at this time, so that the precombustion chamber fuel injector stops working, thereby balancing the system power and economy.

[0088] It should be noted that the person skilled in the art can set the size of the preset system output power according to the actual situation, and the present application is not limited.

[0089] In one possible implementation, when the system mode is the motion mode, optimizing the power generation capacity of the jet piloted free piston power generation system specifically includes:

[0090] The cylinder wall temperature is detected by a cylinder wall temperature sensor.

[0091] According to the cylinder wall temperature, the in-cylinder combustion state is determined.

[0092] When the cylinder wall temperature is lower than the preset wall temperature, the second fuel injector is activated by the control system to switch the combustion mode to the diffusion combustion mode, optimize the power generation capacity of the jet piloted free piston power generation system, and improve the system power of the jet piloted free piston power generation system.

[0093] It should be noted that the person skilled in the art can set the size of the preset wall temperature according to the actual situation, and the present application is not limited.

[0094] It should be noted that the cylinder wall temperature is monitored in real time by the cylinder wall temperature sensor, the in-cylinder combustion state is accurately determined, when the temperature is lower than the preset value, the system automatically adjusts the combustion process, improves the combustion completeness and power output, and ensures the efficient and stable operation of the system under high power demand.

[0095] Specifically, when the system switches to the motion mode, the system needs good power at this time, the cylinder wall temperature is detected by the cylinder wall temperature sensor to determine the in-cylinder combustion state, when the cylinder wall temperature is lower than 100℃, the in-cylinder combustion process is insufficient at this time, the upper computer sends instructions to the control ECU, in the diffusion combustion mode, the pre-chamber fuel injector and the main combustion chamber fuel injector are increased in pulse width, which is used to speed up the combustion speed and improve the system power; in the premixed combustion mode, the intake pipe fuel injector is cut off, the main combustion chamber fuel injector is started, the system combustion mode is changed from premixed combustion to diffusion combustion, the stability of flame propagation is increased, and the system power is improved.

[0096] In one possible implementation, when the system mode is the energy saving mode, optimizing the power generation capacity of the jet piloted free piston power generation system specifically includes:

[0097] The oxygen concentration in the exhaust gas is detected by an oxygen sensor.

[0098] According to the oxygen concentration, the air-fuel ratio of the jet piloted free piston power generation system in the cylinder is determined.

[0099] When the air-fuel ratio is lower than the preset air-fuel ratio, the first fuel injector is activated by the control system to switch the combustion mode to the premixed mode, optimize the power generation capacity of the jet piloted free piston generator system, and improve the system economy of the jet piloted free piston generator system.

[0100] It should be noted that the size of the preset air-fuel ratio can be set by the person skilled in the art according to the actual situation, and the present application is not limited.

[0101] It should be noted that the oxygen sensor is used to detect the oxygen concentration of the exhaust gas in real time, accurately determine the air-fuel ratio of the combustion, and timely adjust the combustion process to ensure more complete combustion, realize lean combustion to reduce fuel consumption, improve system economy and emission performance, and meet the energy saving and environmental protection requirements.

[0102] Specifically, when the system switches to the energy saving mode, good economy is required at this time, the oxygen concentration in the exhaust gas is detected by the oxygen sensor to determine the air-fuel ratio of the current in-cylinder combustion of the system, when the air-fuel ratio is lower than 14.5, the upper computer sends an instruction to the control ECU to make the pre-chamber fuel injector start working, and at the same time, the main combustion chamber fuel injector injection pulse width is reduced to increase the system air-fuel ratio, realize lean combustion, reduce fuel consumption, improve emissions, and improve system economy.

[0103] The technical scheme provided by the embodiment of the present application has at least the following beneficial effects:

[0104] In the present application, according to the operating state of the jet piloted free piston generator system, the control system sends a control signal to control the fuel injector, flexibly switches the pre-chamber jet mode and the main combustion chamber combustion mode, improves the combustion efficiency, and improves the system in-cylinder combustion process, so that the system can better adapt to different working modes, effectively expand the fuel applicability of the free piston internal combustion generator, and promote the use and development of the free piston internal combustion generator technology.

[0105] The present application covers any substitution, modification, equivalent method and scheme made on the essence and scope of the present application. In order to make the public have a thorough understanding of the present application, specific details are described in the preferred embodiments of the present application, and the present application can also be completely understood without the description of these details for the person skilled in the art. In addition, in order to avoid unnecessary confusion to the essence of the present application, well-known methods, processes, procedures, elements and circuits are not described in detail.

[0106] The above is only the preferred embodiment of the present application, and it should be pointed out that for ordinary skilled in the art, without departing from the principle of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present application.

Claims

1. A variable combustion jet-ignited free piston power generation system, characterized in that: include: Linear motor, connecting rod assembly, jet-ignited free piston engine, state acquisition system and control system; The linear motor is connected to the jet-ignition free piston engine via a connecting rod assembly; The jet-ignited free piston engine comprises a cylinder (11), a piston (12) and a pre-combustion chamber (18); The air intake pipe and the main combustion chamber of the cylinder (11) are respectively equipped with a first fuel injector (9) and a second fuel injector (15); A third fuel injector (17) is installed in the pre-combustion chamber (18); The operating state of the jet-ignited free piston power generation system is collected by the state collection system, and the operating state is transmitted to the control system, and a control signal is sent by the control system to control the first fuel injector (9), the second fuel injector (15) and the third fuel injector (17); The state acquisition system includes a linear motor displacement sensor (4), an in-cylinder pressure sensor (16), a cylinder wall temperature sensor (20), and an oxygen sensor (21); The control method of the variable combustion jet-ignited free piston power generation system includes: S1: collecting the operating status of the jet-ignited free piston power generation system through the status acquisition system; S2: optimizing the power generation capacity of the jet-ignited free piston power generation system using the control system in different system modes according to the operating state; The system modes include normal mode, sports mode and energy-saving mode; When the system mode is the normal mode, the optimizing the power generation capacity of the jet-ignited free piston power generation system specifically includes: The gas pressure in the cylinder and the system position information of the jet-ignited free piston power generation system are respectively detected by the in-cylinder pressure sensor and the linear motor displacement sensor; determining the system output power of the jet-ignited free piston power generation system based on the gas pressure and the system position information; When the system output power is lower than a preset system output power, the control system is used to control and activate the third injector, switch the jet mode to an active jet mode, optimize the power generation capacity of the jet-ignited free piston power generation system, and improve the work capacity of the jet-ignited free piston power generation system; When the system output power is higher than a preset system output power, the control system is used to control the third injector to be cut off, so as to avoid waste of the output power of the jet-ignited free piston power generation system.

2. The variable combustion jet-ignited free piston power generation system according to claim 1, characterized in that: The linear motor comprises a mover (1), a stator (2) and a motor housing (3); A permanent magnet is installed inside the linear motor to generate a magnetic field, driving the mover (1) to perform linear motion.

3. The variable combustion jet-ignited free piston power generation system according to claim 1, characterized in that: The first fuel injector (9) and the second fuel injector (15) are used to adapt to different combustion modes of the jet-ignited free-piston internal combustion generator; The third injector (17) is used to switch the injection mode; A spark plug (19) is installed inside the pre-combustion chamber (18), and the spark plug (19) is used to ignite the mixed gas in the pre-combustion chamber.

4. The variable combustion jet-ignited free piston power generation system according to claim 2, characterized in that: The connecting rod assembly comprises a motor end spring seat (5), a spring (6), a connecting rod (7) and a piston end spring seat (8); The spring (6) is arranged between the motor end spring seat (5) and the piston end spring seat (8), and is sleeved on the connecting rod (7); The two ends of the connecting rod (7) are respectively connected to the main shaft of the mover (1) and the piston (12) via bolts.

5. The variable combustion jet-ignited free piston power generation system according to claim 1, characterized in that: The linear motor displacement sensor (4) is mounted on the motor housing (3) and is used to record position information of the jet-ignited free piston power generation system during operation; The in-cylinder pressure sensor (16) is installed in the top area of ​​the cylinder head of the main combustion chamber of the cylinder body (11) and is used to record the change of the gas pressure in the main combustion chamber during the operation of the jet-ignited free piston power generation system; The cylinder wall temperature sensor (20) is installed in the middle area of ​​the cylinder head and is used to record the temperature change of the cylinder wall of the jet ignition free piston power generation system during operation; The oxygen sensor (21) is installed in the exhaust pipe and is used to record the oxygen concentration of the exhaust gas generated by the jet-ignited free piston power generation system during operation.

6. The variable combustion jet-ignited free piston power generation system according to claim 1, characterized in that: The control system includes a host computer and a control ECU; The control ECU is connected to the first fuel injector (9), the second fuel injector (15), the third fuel injector (17), the spark plug (19), the state acquisition system and the motor controller respectively through connecting lines; The state acquisition system transmits the acquired data to the host computer, and the host computer analyzes the combustion process in the cylinder according to the acquired data and transmits a control signal to the control ECU.

7. The control method according to claim 1, characterized in that: When the system mode is the motion mode, the optimizing the power generation capacity of the jet-ignited free piston power generation system specifically includes: Detecting the cylinder wall temperature by the cylinder wall temperature sensor; determining a combustion state in the cylinder according to the cylinder wall temperature; When the cylinder wall temperature is lower than the preset wall temperature, the control system is used to control the activation of the second injector, switch the combustion mode to the diffusion combustion mode, optimize the power generation capacity of the jet-ignited free piston power generation system, and improve the system dynamics of the jet-ignited free piston power generation system.

8. The control method according to claim 1, characterized in that: When the system mode is the energy-saving mode, the optimization of the power generation capacity of the jet-ignited free piston power generation system specifically includes: Detecting the oxygen concentration in the exhaust gas by the oxygen sensor; determining an air-fuel ratio of combustion in the cylinder by the jet-ignited free piston power generation system according to the oxygen concentration; When the air-fuel ratio is lower than a preset air-fuel ratio, the control system is used to control the activation of the first injector, switch the combustion mode to the premixed mode, optimize the power generation capacity of the jet-ignited free piston power generation system, and improve the system economy of the jet-ignited free piston power generation system.

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