What Is a Heat Engine?
Heat engine refers to various machines that use internal energy to do work. It is a type of machine power machinery that converts chemical energy of fuel into internal energy and then mechanical energy, such as steam engines, steam turbines, gas turbines, internal combustion engines, and jet engines.
- Heat engine plays an important role in human life. Modern transportation is powered by it. The application and development of the heat engine promotes the rapid development of society, and it inevitably loses some energy and causes a certain degree of pollution to the environment.
- For the gasoline engine to work continuously, the piston must return to its original position after pushing the crankshaft so as to push the crankshaft again. This requires the piston to be able to reciprocate in the cylinder. The piston moves from one end of the cylinder to the other end of the cylinder in a reciprocating motion called a stroke.
- Four strokes of the heat engine:
- Thermodynamic process [6]
| cycle | Process: points 1 to 2 (compression) | Process: Point 2-Point 3 (heating) | Process: Point 3-Point 4 (Inflated) | Process: Point 4-point 1 (cool down) | Notes |
|---|---|---|---|---|---|
| Cycles usually associated with external combustion engines | |||||
| Brayton cycle | Adiabatic | Isobaric | Adiabatic | Isobaric | Inverse process of the Brayton cycle |
| Kano cycle | Isentropic | Isothermal | Isentropic | Isothermal | |
| Ericsson loop | Isothermal | Isobaric | Isothermal | Isobaric | Known as "Second Ericsson Cycle" from 1853 |
| Rankine cycle | Adiabatic | Isobaric | Adiabatic | Isobaric | Steam engine |
| Scuderi loop | Adiabatic | Variable pressure | Adiabatic | Isovolum | |
| Stirling cycle | Isothermal | Isovolum | Isothermal | Isovolum | |
| Stoddard cycle | Adiabatic | Isobaric | Adiabatic | Isobaric | |
| Cycles usually associated with internal combustion engines | |||||
| Brayton cycle | Adiabatic | Isobaric | Adiabatic | Isobaric | Jet engines began in 1833, and the external combustion engine version of the cycle was called the "First Ericsson Cycle" |
| Diesel cycle | Adiabatic | Isobaric | Adiabatic | Isovolum | Diesel engines |
| Lenoir cycle | Isobaric | Isovolum | Adiabatic | Pulse jet engine process 1-2 completes both compression and heating processes | |
| Otto cycle | Adiabatic | Isovolum | Adiabatic | Isovolum | Petrol engine |