Free piston linear generator based on waste heat utilization

[0017] Example 1

[0018] A free-piston linear generator based on waste heat utilization mainly includes: a free-piston internal combustion engine, a linear generator, and an exhaust gas expansion cylinder. Its free-piston internal combustion engine mainly includes: injector 1, air inlet 2, exhaust port 3, piston 4, internal combustion engine cylinder 5; linear generator includes: motor stator 6, motor mover 7; exhaust gas utilization components include: bleed pipe 8. Intake valve 11, exhaust valve 10, return piston 9, return cylinder 13, water injector 12.

[0019] The specific connection relationship is as follows: the return piston 9 is placed in the return cylinder 13; the water sprayer 12 is installed on the return cylinder 13; 11 is connected; the return piston 9 is connected with one end of the linear motor mover 7; the other end of the linear motor mover 7 is connected with the piston 4 of the free piston internal combustion engine, and the return piston 9, the motor mover 7 and the internal combustion engine piston 4 constitute a moving component.

[0020] 1) Startup process. At this time, the linear generator works in the motor mode, the motor mover 7 pushes the moving component to move, and the piston 4 compresses the gas in the cylinder 5 of the internal combustion engine. The injector 1 of the free-piston internal combustion engine then injects fuel into the cylinder. The fuel burns under high pressure to perform work, which pushes the moving components to move in the opposite direction. The start-up process is now complete.

[0021] 2) Running process. During this stage of work, the system works in a reciprocating manner. At the beginning of a cycle, the piston 4 of the internal combustion engine is at the top dead center position, the fuel injector 1 injects fuel into the cylinder, and the high-pressure gas after combustion pushes the moving component to move. At this time, the linear generator works outwards and outputs electric energy in generator mode. And the exhaust valve 10 of the recovery cylinder is opened, the intake valve 11 is closed, and the gas pressure in the recovery cylinder 13 is consistent with the environment, maintaining a relatively low pressure state. When the gas in the internal combustion engine cylinder 5 expands for a period of time, its exhaust port 3 is opened, and the high temperature and high pressure exhaust gas is introduced into the intake pipe 8 . At the same time, close the exhaust valve 10 of the return cylinder and open its intake valve 11; open the intake port 2 of the free-piston internal combustion engine to ventilate the internal combustion engine cylinder 5, and the moving component reaches the bottom dead center. When the exhaust gas enters the recovery cylinder 13 through the intake pipe 8, the exhaust valve 11 of the recovery cylinder is closed, and the water sprayer 12 sprays water into the recovery cylinder 13. The water absorbs heat from the high-temperature exhaust gas and vaporizes, forming high-pressure steam and starting to push the moving components back to the top dead center. Then start the next cycle.