CN114856840A

CN114856840A - Full-electric control free piston four-stroke internal combustion power generation system

Info

Publication number: CN114856840A
Application number: CN202110224624.1A
Authority: CN
Inventors: 傅强
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-03-01
Filing date: 2021-03-01
Publication date: 2022-08-05

Abstract

The invention discloses a full-electric control free piston four-stroke internal combustion power generation system, which does not have a mechanical device to maintain or assist the cycle work of an internal combustion engine and is a system for realizing the four-stroke cycle work and power generation by completely controlling a linear motor to drive a free piston through software based on the output power, the charging power, the thermal efficiency, the safety requirement, a detector and the input operation amount. The system comprises an internal combustion engine part, a linear motor part, an information detection part, a control part, an energy storage part and an input operation amount. The internal combustion engine part abandons parts such as a crankshaft and the like for mechanically maintaining circulation and limiting working stroke, the free piston is not in rigid or elastic permanent connection with a cylinder or other mechanical devices, the linear motor is completely controlled by software to drive the linear motor to complete exhaust, air suction and compression strokes, and the working stroke is completely controlled by the software according to input operation amount, detected output power and charging power to complete the linear generator. The safety devices of the control part and the internal combustion engine part provide a solution for the safe movement of the free piston.

Description

Full-electric control free piston four-stroke internal combustion power generation system

Technical Field

The invention relates to the fields of machinery, electric power, electronics and software. .

Background

In the traditional piston type four-stroke internal combustion engine, a plurality of mechanical structures such as a crankshaft, a piston connecting rod, a flywheel and the like are arranged for cyclic operation, so that the mechanical friction and the motion inertia are increased, and the thermal efficiency and the power response speed are not favorably improved. More importantly, the crankshaft limits the piston to only perform equal-stroke motion, so that the traditional internal combustion engine can only obtain higher thermal efficiency within a narrow power range, and a flat efficiency curve and higher thermal efficiency are difficult to realize. In addition, the complex kinematic structure of the conventional internal combustion engine also brings about a complex cooling and lubricating structure.

The linear motor has linear reciprocating driving capability and can also work reversely to become a linear generator.

The computer is configured with electronic and electrical components to allow software programming to control machine operation.

The prior literature is available.

Disclosure of Invention

The problems to be solved by the present invention are as follows: the four-stroke internal combustion engine has the advantages of reducing the friction force of the four-stroke internal combustion engine, reducing the motion inertia, realizing various circulation modes, realizing the combustion work of various fuels, improving the energy conversion efficiency, realizing a flat efficiency curve, simplifying the lubricating and cooling structure and solving the safety problem of system operation.

Solution scheme

The invention relates to an all-electric control free piston four-stroke internal combustion power generation system, which has no mechanical device to maintain or assist the cycle work of an internal combustion engine, and is a system which completely drives a free piston by a software-controlled linear motor to realize the four-stroke cycle work and generate power based on output power, charging power, thermal efficiency, safety requirements, a detector and input operation amount, wherein the output power is the power output by the all-electric control free piston four-stroke internal combustion power generation system 1000 to an external load 600, and the charging power is the power for the all-electric control free piston four-stroke internal combustion power generation system 1000 to charge an energy storage part 500 contained in the all-electric control free piston four-stroke internal combustion power generation system 1000 comprises: a linear motor part 400 including a linear generator 405 and a linear motor 404; an internal combustion engine part 300, which works according to four strokes of air intake, compression, work application and air exhaust; an energy storage unit 500 composed of an electricity storage device; an information detection unit 100 that detects a position of a piston 308 included in the internal combustion engine unit 300, the output power, and the charging power; an input operation amount 700 that is a parameter that changes the output power and the operating state of the internal combustion engine section 300; a control unit 200 for calculating and controlling the linear motor unit 400, controlling the output power and the charging power, and controlling the operation state of the internal combustion engine unit 300, based on the data detected by the information detection unit 100, the thermal efficiency, the safety requirement, and the input operation amount 700; a control method.

The internal combustion engine 300 is characterized in that: the four-stroke working mode of air inlet, compression, work application and air exhaust is adopted; a free piston 308 is arranged in a cylinder 310, and the piston 308 is not permanently connected with the cylinder 310 or other devices contained in the internal combustion engine part 300 in any rigid or elastic way; the working dead center and the limit dead center of the piston 308 are set by the control part 200 and the information detection part 100 together, the working dead center comprises a working top dead center and a working bottom dead center, the limit dead center comprises a limit top dead center and a limit bottom dead center, and the limit dead center at least covers the position range of the working dead center along the axial direction of the cylinder 310; the air intake actuator 301, the air exhaust actuator 302, the fuel injection actuator 303 and the ignition actuator 305 are arranged above the limit top dead center of the cylinder 310, and the fuel injection actuator 303 and the ignition actuator 305 can be selectively used or not used according to different fuels or combustion modes; below the extreme bottom dead center of the cylinder 310 is disposed an intake exhaust port 309 by which the lower air pressure of the cylinder 310 is maintained stable as the piston 308 moves; a lubricating oil injection actuator 304, an oil return 311 and a safety elastic device 307 are arranged below the limit bottom dead center of the cylinder 310; the lubricating oil is injected to the piston 308 and the inner wall of the cylinder 310 by the lubricating oil injection actuator 304 to reduce the sliding friction force and is collected by backflow through the oil return opening 311; the safety elastic means 307 prevents the piston 308 from striking the bottom of the cylinder 310 by its participation in the abnormal or failure condition of the control portion 200; a safety exhaust valve 306 is disposed at or below the limit bottom dead center of the cylinder 310, by which the gas pressure in the cylinder 310 is safely released when the control portion 200 is abnormal or fails; the piston 308 drives the linear generator 405 to generate power in the working stroke, and the other three strokes are completed by driving the piston 308 by the linear motor 404;

the energy storage part 500 is characterized in that: the output power is buffered and regulated, and working electric energy is provided for the full-electric control free piston four-stroke internal combustion power generation system 1000; the energy storage part 500 may be one type of power storage device or a combination of multiple types of power storage devices; the energy storage part 500 may be connected in series or in parallel with the load 600.

The linear motor unit 400 is characterized in that: the linear motor mover 403 may be a permanent magnet or an induction coil, or a combination of the two; the linear motor rotor 403 and the linear motor stator 401 form a linear motor 404; the linear motor rotor 403 and the linear generator stator 402 form a linear generator 405; the linear motor rotor 403 and the piston 308 are combined and fixed to form a piston rotor assembly; the linear motor stator 401 and the linear generator stator 402 are coated on the outer wall of the cylinder 310, and cover the working stroke of the piston mover assembly along the axial length of the cylinder 310; the linear motor stator 401 and the linear generator stator 402 may be separately configured to operate independently, or may be integrated to change the operation attribute according to the stroke; the stator of the linear motor 401, the stator of the linear generator 402 and the mover 403 may not form a continuous uniform magnetic field on a cross section perpendicular to the axial direction of the cylinder 310, otherwise the piston 308 may not be inhibited from rotating around the axis during operation.

The information detection unit 100 is characterized in that: the device at least comprises an output power detector 101, a charging power detector 102, a piston position detector 103 and a position calibrator 104; the piston position detector 103 and the position calibrator 104 form a non-contact detector unit, and are used for acquiring the specific axial position of the piston 308 in the cylinder 310; the position marker 104 is disposed on the surface of the piston 308 closest to the inner wall of the cylinder 310 along the axial direction of the piston 308, and may be provided in plurality; the piston position detector 103 is provided with at least two piston position detector columns, and the piston position detector columns are arranged on the outer wall of the cylinder 310 along the axial direction of the cylinder 310 and are aligned with the position marker 104.

The control unit 200 is characterized in that: the ECU202 manages the operation of the all-electrically controlled free-piston four-stroke internal combustion power generation system 1000; the control right of the safety protection module 201 is higher than that of the ECU 202; the safety protection module 201 monitors the position of the piston 308 in real time through the information detection part 100, when the piston 308 is judged to reach the limit dead point, the safety protection module 201 takes over the control right of the ECU202, opens the exhaust actuator 302, closes the linear motor 404, manipulates other actuators included in the internal combustion engine part 300 required, and waits for the piston 308 to return to the stroke range determined by the limit dead point and then returns the control right to the ECU 202; the power management module 203 manages the power usage of the fully electrically controlled free piston four-stroke internal combustion power generation system 10000 including rectification and shaping of the power output by the load 600.

The 700 input control quantity is characterized in that: the control section 200 is supplied with external control information such as power demand, fuel type, thermal efficiency, vibration, and the like.

A plurality of fuel cells, each of which is composed of the internal combustion engine 300, the probe included in the information detection unit 100 attached thereto, and the linear motor unit 400, may be connected in parallel, and share the control unit 200.

The control method is characterized in that: the control unit 200 generates an operation schedule based on the input control quantity 700, the information provided by the information detection unit 100, and preset information built in the control unit 200, and the control unit 200 controls the operation and exception handling of the all-electric control free-piston four-stroke internal combustion power generation system according to the operation schedule and the real-time information provided by the information detection unit 100, and the basic operation mode is as follows: the control part 200 generates an operation plan based on the input control quantity 700, the information provided by the information detection part 100 and preset information built in the control part 200, wherein the operation plan at least comprises the fuel injection quantity and time, the air suction quantity and time, the ignition time, the exhaust time, the lubricating oil distribution time of the operation cycle of the internal combustion engine part 300, and the operation top dead center, the operation bottom dead center, the movement speed and the time of the piston 308 in each stroke, and the operation plan also comprises the operation sequence of each piston 308 when the fuel cells are connected in parallel; an exhaust stroke, wherein the control unit 200 controls the exhaust actuator 302 and other actuators included in the internal combustion engine 300 based on the operation schedule and the real-time information provided by the information detection unit 100, and controls the linear motor 404 to drive the piston 308 to move up to the stroke operation top dead center; an intake stroke, wherein the control unit 200 controls the intake actuator 301, the exhaust actuator 302, and another actuator included in the internal combustion engine 300 based on the operation schedule and the real-time information provided by the information detection unit 100, and controls the linear motor 404 to drive the piston 308 to the stroke operation bottom dead center; a compression stroke, in which the control unit 200 controls the intake actuator 301, the exhaust actuator 302, and other actuators included in the internal combustion engine unit 300 based on the operation schedule and the real-time information provided by the information detection unit 100, and controls the linear motor 404 to drive the piston 308 to the stroke operation top dead center; the control part 200 controls the ignition actuator 305 and other actuators included in the internal combustion engine part 300 to ignite or the fuel mixture to self-ignite to push the piston 308 to move downwards to drive the linear generator 405 to generate electricity based on the work plan and the real-time information provided by the information detection part 100, and adjusts and limits the linear generator 405 to output electric energy to the load 600 and the energy storage part 500; in the subsequent stroke, the control unit 200 controls the internal combustion engine unit 300 to continue the circulation operation or stop the circulation operation based on the information provided from the information detection unit 100, the input operation amount 700, and the result of the previous stroke. And (4) performing exception processing, wherein when the internal combustion engine part 300 and the linear motor part 400 have an exception condition which is contrary to the working plan in any stroke, the control part 200 controls the exhaust actuator 302 and other actuators or linear motors 404 contained in the control part 200 to release the pressure of the cylinder 310, and gives an alarm to finish the operation of the internal combustion engine part 300.

Drawings

Fig. 1 is a block diagram showing the configuration of an all-electrically controlled free-piston four-stroke internal combustion power generation system according to the embodiment.

Fig. 2 is a structural view illustrating the linear motor, the piston, the position marker, and the piston position detector of fig. 1.

Fig. 3 is an electrical block diagram illustrating fig. 1.

Fig. 4 is a software basic flowchart illustrating the ECU of fig. 3.

Description of the reference numerals

100 information detection part, 101 output power detector, 102 charging power detector, 103 piston position detector, 104 position calibrator, 200 control part, 201 safety protection module, 202 ECU, 203 power management module, 300 internal combustion engine part, 301 air inlet actuator, 302 air outlet actuator, 303 fuel injection actuator, 304 lubricating oil injection actuator, 305 ignition actuator, 306 safety exhaust valve, 307 safety elastic device, 308 piston, 309 air inlet and outlet, 310 cylinder, 311 oil return port, 400 linear motor part, 401 linear motor stator, 402 linear motor stator, 403 linear motor mover, 404 linear motor, 405 linear motor, 500 energy storage part, 600 load, 700 input operation amount, 800 cable pipeline.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings. In the following description, the same or corresponding elements are denoted by the same reference numerals, and redundant description thereof is omitted.

Fig. 1 is a block diagram showing the configuration of an all-electrically-controlled free-piston four-stroke internal combustion power generation system 1000 according to an embodiment (unless otherwise noted, the all-electrically-controlled free-piston four-stroke internal combustion power generation system 1000 will be simply referred to as the system 1000 in the following description), fig. 2 is a block diagram showing the configuration of a linear generator unit 400, a piston 308, a position marker 104, and a piston position detector 103 in fig. 1, fig. 3 is an electrical block diagram showing fig. 1, and fig. 4 is a software basic flowchart showing an ecu (electronic Control unit)202 in fig. 3. As shown in fig. 1 and 2, the system 1000 includes: the information detection part 100, the control part 200, the internal combustion engine part 300, the linear motor part 400, the energy storage part 500, the input control quantity 700, the cable pipeline 800 and the load 600 are not components of the system 1000, and are only numbered for convenience of description.

The information detection unit 100 is a combination of detection devices that acquire information to ensure the continuous operation of the system 1000. The information detecting unit 100 includes at least a piston position detector 103, a position marker 104, an output power detector 101, and a charging power detector 102.

The piston position detector 103 detects the position of the position marker 104 and the position of the piston 308 in the cylinder 310. As shown in fig. 2, since the cylinder 310 is a closed container and is not transparent, the piston position detector 103 is usually a non-contact magnetic detector such as a hall sensor, the corresponding position marker 104 is a magnetic device, and both should be kept away from the linear motor part 400 to reduce magnetic field interference. The position marker 104 is arranged on the surface of the piston 308 closest to the inner wall of the cylinder 310 along the axial direction of the piston 308, the piston position detectors 103 are arranged on the outer wall of the cylinder 310 along the axial direction to form a detector column, and the position marker 104 is monitored in real time to obtain the axial specific position of the piston 308 in the cylinder 310.

As shown in fig. 2, at least one position marker 104 is disposed on the corresponding side of the detector array, and two or more position markers are disposed to form a marker array for improving reliability. In addition, the same row of calibrators should be placed on the other side of the piston 308 symmetry.

The reason why the piston position detector 103 is at least a single row and the position indicator 104 is at least a plurality of rows is that the piston 308 may rotate around the axis during operation, and the two or even more rows of position indicators 104 ensure that the piston position detector 103 detects information when it rotates. A method of suppressing the rotation of the piston 308 is described in the description of the linear motor section 400.

As a simplified detection method, when the piston position detector 103 is a magnetic detection device such as a hall sensor, the position marker 104 may also be replaced by the linear motor mover 403, because the linear motor mover also generates a magnetic field.

The output power detector 101 is a detector for detecting the actual power output from the power management module 203 to the load 600, and detects the current and voltage of the output circuit to calculate the output power.

The charging power detector 102 is a detector that detects the actual charging power of the energy storage unit 500 by the power management module 203, and detects the current and voltage of the charging circuit to calculate the charging power.

The energy storage unit 500 may be a single energy storage device such as a ternary lithium battery, or may be a combination of multiple types such as a super capacitor and a ternary lithium battery. The function of the buffer is to provide working power for each part of the system 1000, and also to buffer and regulate the power generated by the linear generator 405.

The cable conduit 800 is a generic term for cables, signal lines, and the like that connect the various components of the system 1000.

The load 600 is a general term for the system 1000 to output power externally, and is not a component of the system 1000, and is numbered only for convenience of description.

The linear motor part 400 includes a linear generator 405 and a linear motor 404. The linear motor 404 is a power unit that drives the piston 308 to perform three strokes of exhaust, intake, and compression, and the linear generator 405 is an electric power unit that is driven by the piston 308 to generate power in the power stroke. Because the motor can work reversely to become a generator, the motor and the generator can be the same entity, and the working property is changed only when needed; of course, the two entities may be separate entities. As shown in fig. 2, the present embodiment is described by taking the same entity as the above, and the reference numerals only indicate the operation attributes corresponding to each trip when the internal combustion engine 300 is operating.

As shown in fig. 2, the mover 403 of the linear motor part 400 is fixed to the piston 308, and the linear generator stator 402 and the linear motor stator 401 are coated on the outer wall of the cylinder 310, and cover at least the operating stroke of the piston 308 along the axial length of the cylinder 310.

Magnetic restraint is required because the piston 308 may rotate about its axis during operation without the piston rod limitations of conventional internal combustion engines. As shown in fig. 2, the cross-sections of linear motor stator 401, linear generator stator 402 and mover 403 are not continuous and uniform in order to inhibit possible rotation of piston 308 during movement.

The internal combustion engine 300 eliminates the components such as crankshaft, flywheel, connecting rod, etc. that maintain the circulation mechanically and limit the working stroke of the piston in the traditional internal combustion engine, and only retains the necessary working components and auxiliary components, including: an air inlet actuator 301, an air outlet actuator 302, a fuel injection actuator 303, a lubricating oil injection actuator 304, an ignition actuator 305, a safety exhaust valve 306, a safety elastic device 307, a piston 308, an air inlet and outlet 309, a cylinder 310 and an oil return opening 311.

As shown in FIG. 1, a piston 308 is arranged in a cylinder 310, an air inlet actuator 301, an air outlet actuator 302, a fuel injection actuator 303 and an ignition actuator 305 are arranged at the top of the cylinder 310, a safety exhaust valve 306 is arranged at the middle lower part of the cylinder 310, an air inlet and exhaust port 309 is arranged at the lower part of the cylinder 310, a lubricating oil injection actuator 304 and an oil return port 311 are arranged at the lower part or bottom of the cylinder 310, and a safety elastic device 307 is arranged in the cylinder 310.

The piston 308 is a free piston that slides in contact with the inner wall of the cylinder 310 without any permanent rigid or elastic connection to other components of the engine part 300. Similar to a conventional piston for an internal combustion engine, the piston 308 may be provided with a piston ring to achieve sealing and friction reduction effects, and may also be provided with an oil ring and oil holes to achieve better lubrication effects. Fig. 1 and 2 are shown but not numbered because they belong to the public general technology.

The fuel injection actuator 303 and the ignition actuator 305 may be selectively used or not used according to different fuels or combustion modes, and the combustible mixture is introduced by the air intake actuator 301 when the fuel injection actuator 303 is not used. For example, using gasoline fuel requires the use of an ignition actuator 305, and further using direct injection requires the use of a fuel injection actuator 303. Second, the use of diesel fuel eliminates the need for the ignition actuator 305, but requires the fuel injection actuator 303.

Because a crankshaft and a piston connecting rod of the traditional internal combustion engine do not exist, the cylinder lubricating oil distribution mode is different from the splash mode of the traditional internal combustion engine, and the spray mode is adopted in the embodiment. As shown in fig. 1, the lubricant injection actuator 304 may inject the lubricant directly toward the inner wall of the cylinder 310 or the bottom of the piston 308, and the excess lubricant may be collected via the return 311. The mode has better application effect and saves more lubricating oil.

The actuators included in the internal combustion engine 300 are generally electrically controlled actuators, and are controlled by the ECU 202.

The intake and exhaust ports 309 are used to address the "bellows effect" of the piston 308 during operation, keeping the air pressure in the cavity between the bottom of the piston 308 and the bottom of the cylinder 310 constant, and eliminating adverse effects on the operation of the piston 308.

The control unit 200 includes at least three units, namely, an ECU202, a safety protection module 201, and a power management module 203.

The ECU202 is an electronic control Unit having a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like. In the ECU202, various controls are executed by loading programs stored in the ROM into the RAM and executing them by the CPU. The ECU202 may be constituted by a plurality of electronic control units.

The safety protection module 201 may be an electronic control unit such as the ECU202, or may be a simple hardware circuit, and all basic functions are to acquire and determine information provided by the information detection unit 100 in real time to ensure safe operation of the system 1000.

The power management module 203 is a set of a rectification shaping switching circuit output by the linear generator 405, a linear motor 404 driving circuit, each electric control actuator driving circuit included in the internal combustion engine part 300, an energy storage part charging circuit, each part power supply circuit of the system 1000, and the like, and is controlled by the ECU 202.

The input control amount 700 is control information derived from power demand, fuel type, thermal efficiency, vibration, and the like outside the system 1000. Further, the vibration information is not limited to the external input, and a part of the vibration information may be provided by the information detection portion 100 integrated with the vibration detector.

A typical operation of the system 1000 will now be described with reference to fig. 1-4, wherein the fuel type is gasoline and in-cylinder direct injection is used.

First, the ECU202 receives input control quantities 700 including information on power demand, fuel type, thermal efficiency, vibration, etc. from the outside, and integrates other information preset inside the ECU202 to set or change an operation schedule. The input control amount 700 contains information that is somewhat of a stability, such as fuel type, that does not change until the system 1000 is shut down; some of this information is of a relatively stable type, such as thermal efficiency, and the information changes less frequently during the system 1000 operating cycle; some of these are of the frequent type, for example power requirements, vibrations, which change over time and thus affect the individual working strokes of the internal combustion engine part 300. The ECU202 needs to make a corresponding work plan according to these characteristics and respond to the changes in time.

The working plan includes the stop point and movement speed and time of the piston 308 in each stroke, the fuel injection amount and time, the air intake amount and time, the ignition time, the exhaust time, the lubricating oil distribution amount and time, and the like, and when the multiple cylinders are connected in parallel, the working plan further includes the sequence of the strokes of the cylinders, and the like. The dead points are divided into an upper dead point and a lower dead point, and the dead points of all strokes are different. For example, exhaust stroke top dead center coincides with intake stroke top dead center, but compression stroke top dead center may be lower than intake stroke top dead center to achieve different compression ratios; if the compression stroke bottom dead center is consistent with the intake stroke bottom dead center, the power stroke bottom dead center can be lower or higher than the intake stroke bottom dead center so as to realize different thermal efficiency and power output.

The internal combustion engine 300 has an exhaust stroke, an intake stroke, a compression stroke, and a power stroke as one cycle period. The work plan may be formulated or adjusted and executed on a per cycle basis.

In the exhaust stroke, the ECU202 closes the air inlet actuator 301, opens the exhaust actuator 302 and controls the linear motor 404 to push the piston 308 upwards according to the working schedule. If the exhaust stroke is before the stop state, the piston 308 is located at a certain position of the cylinder 310 under the influence of magnetic force and gravity; if the previous operation is in operation, it may be at bottom dead center of the previous stroke. In the uplink process, the ECU202 monitors the running condition of the piston 308 in real time through the piston position detector 103, and can temporarily adjust the running speed of the piston 308 according to the vibration information provided by the input control quantity 700. If the piston 308 does not reach top dead center for the stroke at the scheduled time, the ECU202 will alarm and end the operation. .

In the intake stroke, after the piston 308 reaches the top dead center of the previous stroke, the ECU202 closes the exhaust actuator 302, opens the intake actuator 301, controls the linear motor 404 to push the piston 308 to move downwards, and controls the fuel injection actuator 303. In the downlink process, the ECU202 monitors the running condition of the piston 308 in real time through the piston position detector 103, and can temporarily adjust the running speed of the piston 308 according to the vibration information provided by the input control quantity 700. If the piston 308 does not reach the bottom dead center of the stroke according to the scheduled time, the ECU202 alarms and finishes the work.

In the compression stroke, after the piston 308 reaches the upper stroke bottom dead center, the ECU202 closes the air intake actuator 301 and controls the linear motor 404 to push the piston 308 to move upwards. In the uplink process, the ECU202 monitors the running condition of the piston 308 in real time through the piston position detector 103, and the ECU202 can temporarily adjust the running speed of the piston 308 according to the vibration information provided by the input control quantity 700. If the piston 308 does not reach the top dead center of travel at the scheduled time, the ECU202 will alarm and end the operation.

In the working stroke, after the piston 308 reaches the top dead center of the previous stroke, the ECU202 controls the ignition actuator 305 to ignite the combustible mixture to expand and work, and the piston 308 moves downwards to drive the linear generator 405 to generate power. The ECU202 monitors the motion of the piston 308 in real time by the piston position detector 103. The ECU202 monitors the power variation in real time through the output power detector 101 and the charging power detector 102 and controls the power management module 203. If the output power exceeds the power demand of the input control amount 700, the charging power to the energy storage portion 500 is increased, and if the charging power of the energy storage portion 500 also reaches the upper limit, the exhaust stroke is advanced to protect the relevant devices included in the system 1000. On the other hand, if the output power is insufficient or the internal resistance of the load 600 becomes small, the speed of the piston 308 is too low or the current of the generator 405 is too large, the exhaust stroke should be entered in advance to stop working, and the ECU202 alarms and ends the work.

On the subsequent stroke, after the piston 308 reaches the upper stroke bottom dead center, the ECU202 opens the exhaust actuator 302, and then judges whether to continue the working cycle or end according to the input control quantity 700 and the alarm.

The ECU202 controls the amount and time of the lubricant distribution by the lubricant injection actuator 304 in each operation cycle according to the operation schedule.

If other fuel types are used instead, only a small number of components of the engine section 300 need be selected to use and modify the operating schedule of the ECU 202.

Safety problem and solution

The traditional internal combustion engine has hard limits on the top dead center and the bottom dead center of the piston because of the crankshaft, and the piston 308 of the invention has no hard limit so as to have the risk of impacting the top and the bottom of the cylinder, wherein the biggest risk is that the electromagnetic force of the linear generator 405 cannot restrict the piston 308 in the power stroke to cause the impact on the bottom of the cylinder, so the solution of the risk must be considered.

Passive security measures:

the safety vent valve 306 may be a one-way valve and the safety elastic device 307 may be a cushioning device such as a spring. When the piston 308 descends beyond the installation position of the safety exhaust valve 306, the gas in the cylinder 310 is automatically exhausted from the safety exhaust valve 306; if the piston 308 continues to move downwards, the kinetic energy is absorbed by the safety elastic device 307 at the bottom of the cylinder 310. The safety exhaust valve 306 may also be a two-way valve that acts as or replaces the intake exhaust port 309 when the piston 308 is operating safely.

Active safety measures:

the control authority of the safeguard module 201 is higher than that of the ECU 202. The safety protection module 201 selects two points of the piston position detector 103 as limit dead points of the piston 308, wherein the limit dead points at least cover working dead points included in a working plan formulated by the ECU202, and the limit dead points comprise a limit upper dead point and a limit lower dead point. The safety protection module 201 monitors the piston position detector 103 in real time, and when the piston 308 reaches the limit dead center, the safety protection module 201 takes over the control of the ECU202, opens the exhaust actuator 302, closes the linear motor 404 and operates other required actuators, and waits for the piston 308 to return to the stroke range determined by the limit dead center and returns the control to the ECU 202.

Cooling structure

In order to reduce the magnetic gap to the maximum extent, the stator of the linear motor part 400 is tightly wrapped on the outer wall of the cylinder 310, and the stator covers the working stroke of the piston 308 along the axial length of the cylinder 310, so one consideration is to design the magnetic conductive material of the stator of the linear motor part 400 into a characteristic shape and also serve as a heat dissipation device; furthermore, the linear motor 400 and the cylinder 310 are both encapsulated in the cooling liquid to achieve better heat dissipation.

Claims

1. A full-electric control free piston four-stroke internal combustion power generation system,

the system is a system which is completely driven by a linear motor controlled by software to realize four-stroke cycle operation and generate power by a linear motor controlled by software based on output power, charging power, thermal efficiency, safety requirements, a detector and input operation amount, wherein the output power is the power output by the full-electric-control free-piston four-stroke internal combustion power generation system 1000 to an external load 600, and the charging power is the power for charging an energy storage part 500 contained in the full-electric-control free-piston four-stroke internal combustion power generation system 1000, and the full-electric-control free-piston four-stroke internal combustion power generation system 1000 comprises:

a linear motor part 400 including a linear generator 405 and a linear motor 404;

an internal combustion engine part 300, which works according to four strokes of air intake, compression, work application and air exhaust;

an energy storage unit 500 composed of an electricity storage device;

an information detection unit 100 that detects a position of a piston 308 included in the internal combustion engine unit 300, the output power, and the charging power;

an input operation amount 700 that is a parameter that changes the output power and the operating state of the internal combustion engine section 300;

a control unit 200 for calculating and controlling the linear motor unit 400, controlling the output power and the charging power, and controlling the operation state of the internal combustion engine unit 300, based on the data detected by the information detection unit 100, the thermal efficiency, the safety requirement, and the input operation amount 700;

a control method.

2. The fully electrically controlled free-piston four-stroke internal combustion power generation system according to claim 1,

the internal combustion engine 300 is characterized in that: the four-stroke working mode of air inlet, compression, work application and air exhaust is adopted; a free piston 308 is arranged in a cylinder 310, and the piston 308 is not permanently connected with the cylinder 310 or other devices contained in the internal combustion engine part 300 in any rigid or elastic way; the working dead center and the limit dead center of the piston 308 are set by the control part 200 and the information detection part 100 together, the working dead center comprises a working top dead center and a working bottom dead center, the limit dead center comprises a limit top dead center and a limit bottom dead center, and the limit dead center at least covers the position range of the working dead center along the axial direction of the cylinder 310; the air intake actuator 301, the air exhaust actuator 302, the fuel injection actuator 303 and the ignition actuator 305 are arranged above the limit top dead center of the cylinder 310, and the fuel injection actuator 303 and the ignition actuator 305 can be selectively used or not used according to different fuels or combustion modes; below the extreme bottom dead center of the cylinder 310 is disposed an intake exhaust port 309 by which the lower air pressure of the cylinder 310 is maintained stable as the piston 308 moves; a lubricating oil injection actuator 304, an oil return 311 and a safety elastic device 307 are arranged below the limit bottom dead center of the cylinder 310; the lubricating oil is injected to the piston 308 and the inner wall of the cylinder 310 by the lubricating oil injection actuator 304 to reduce the sliding friction force and is collected by backflow through the oil return opening 311; the safety elastic means 307 prevents the piston 308 from striking the bottom of the cylinder 310 by its participation in the abnormal or failure condition of the control portion 200; a safety exhaust valve 306 is disposed at or below the limit bottom dead center of the cylinder 310, by which the gas pressure in the cylinder 310 is safely released when the control portion 200 is abnormal or fails; the piston 308 drives the linear generator 405 to generate electricity for the power stroke, and the other three strokes are completed by the linear motor 404 driving the piston 308.

3. The fully electrically controlled free-piston four-stroke internal combustion power generation system according to claim 1,

4. A full-electric control free-piston four-stroke internal combustion power generation system according to claims 1-3,

5. The full-electric control free-piston four-stroke internal combustion power generation system according to claims 1-4,

6. The full-electric control free-piston four-stroke internal combustion power generation system according to claim 1-5,

the control unit 200 is characterized in that: the ECU202 manages the operation of the all-electrically controlled free-piston four-stroke internal combustion power generation system 1000; the control right of the safety protection module 201 is higher than that of the ECU 202; the safety protection module 201 monitors the position of the piston 308 in real time through the information detection part 100, when the piston 308 is judged to reach the limit dead point, the safety protection module 201 takes over the control right of the ECU202, opens the exhaust actuator 302, closes the linear motor 404, manipulates other actuators included in the internal combustion engine part 300 required, and waits for the piston 308 to return to the stroke range determined by the limit dead point and then returns the control right to the ECU; the power management module 203 manages the power usage of the fully electrically controlled free piston four-stroke internal combustion power generation system 10000 including rectification and shaping of the power output by the load 600.

7. The full-electric control free-piston four-stroke internal combustion power generation system according to claims 1-6,

8. The full-electric control free-piston four-stroke internal combustion power generation system according to claims 1-7,

9. A control method of a full-electric control free piston four-stroke internal combustion power generation system,

the full-electric control free-piston four-stroke internal combustion power generation system according to claims 1-8,

the control method is characterized in that: the control unit 200 generates an operation schedule based on the input control quantity 700, the information provided by the information detection unit 100, and preset information built in the control unit 200, and the control unit 200 controls the operation and exception handling of the all-electric control free-piston four-stroke internal combustion power generation system according to the operation schedule and the real-time information provided by the information detection unit 100, and the basic operation mode is as follows:

the control part 200 generates an operation plan based on the input control quantity 700, the information provided by the information detection part 100 and preset information built in the control part 200, wherein the operation plan at least comprises the fuel injection quantity and time, the air suction quantity and time, the ignition time, the exhaust time, the lubricating oil distribution time of the operation cycle of the internal combustion engine part 300, and the operation top dead center, the operation bottom dead center, the movement speed and the time of the piston 308 in each stroke, and the operation plan also comprises the operation sequence of each piston 308 when the fuel cells are connected in parallel;

an exhaust stroke, wherein the control unit 200 controls the exhaust actuator 302 and other actuators included in the internal combustion engine 300 based on the operation schedule and the real-time information provided by the information detection unit 100, and controls the linear motor 404 to drive the piston 308 to move up to the stroke operation top dead center;

an intake stroke, wherein the control unit 200 controls the intake actuator 301, the exhaust actuator 302, and other actuators included in the internal combustion engine 300 based on the operation schedule and the real-time information provided by the information detection unit 100, and controls the linear motor 404 to drive the piston 308 to the stroke operation bottom dead center;

a compression stroke, in which the control unit 200 controls the intake actuator 301, the exhaust actuator 302, and other actuators included in the internal combustion engine unit 300 based on the operation schedule and the real-time information provided by the information detection unit 100, and controls the linear motor 404 to drive the piston 308 to the stroke operation top dead center;

the control part 200 controls the ignition actuator 305 and other actuators included in the internal combustion engine part 300 to ignite or the fuel mixture to self-ignite to push the piston 308 to move downwards to drive the linear generator 405 to generate electricity based on the work plan and the real-time information provided by the information detection part 100, and adjusts and limits the linear generator 405 to output electric energy to the load 600 and the energy storage part 500;

a subsequent stroke in which the control section 200 controls the internal combustion engine section 300 to continue the circulation operation or stop the circulation operation based on the information provided from the information detection section 100, the input operation amount 700, and the result of the previous stroke;

and (4) performing exception processing, wherein when the internal combustion engine part 300 and the linear motor part 400 have an exception condition which is contrary to the working plan in any stroke, the control part 200 controls the exhaust actuator 302 and other actuators or linear motors 404 contained in the control part 200 to release the pressure of the cylinder 310, and gives an alarm to finish the operation of the internal combustion engine part 300.