heat engine - a machine that does the work through the use of fuel energy.The machine working on this engine, converts thermal energy into mechanical energy and apply the substance of the relationship of expansion temperature.
heat engine first appeared in the Roman Empire.It was an external combustion turbine that runs on steam.But because of the poor development of the art, the invention was not developed.On the progress it had no impact and were soon forgotten.Later, in China there was gunpowder cannon and gunpowder rocket.This was a relatively simple device.In terms of the mechanics of powder rocket it was not a heat engine, but from the point of view of physics is a thermal machine.Already in the 17th century, scientists have tried to invent gunpowder-based weapons heat engine.
Types of thermal engines
thermal external combustion engines:
1. Stirling engine - a thermal device in which gaseous or liquid working body makes movements in a confined space.This device is based on a periodic cooling and heating of working fluid.This extracted energy that occurs when the amount of the working fluid.The Stirling engine can be powered by any heat source.
2. Steam engines.Their main advantage - simplicity and excellent traction qualities, which does not affect performance.Thus it is possible to do without the gear.This steam engine is different for the better from the internal combustion engine at low speeds issuing insufficient power.For this reason, a steam engine which is used as a drive motor.Disadvantages: low efficiency, low speed, a constant flow of water and fuel, a lot of weight.Before the steam engine were the only engine.But they require a lot of fuel and freezing in winter.Then they were gradually replaced motors, internal combustion engines, steam and gas turbines, which have a compact, higher efficiency, flexibility and efficiency.
thermal combustion engines:
1. ICE (stands for an internal combustion engine) - it is the engine, which in the process, part of the burning fuel is converted into mechanical energy.Reciprocating internal combustion engines differ in the type of fuel (gas and liquid) for operating cycle (two- or four-stroke), by the method of preparation of the working mixture (carburettor, diesel engines), by type of energy conversion (turbine, combined, piston and jet).The first internal combustion engine was invented and developed by E. Lenoir in 1860.The operating cycle consists of four cycles, for this reason it is also called a four-stroke engine.Currently, such a motor is most often found in vehicles.
2. A rotary internal combustion engine.As an example, an electric thermal station operating in base and peak mode.This type of engine is relatively simple and can be created in any size.Instead of pistons used rotor rotating in a special chamber.In it are located inlets and outlets, and a spark plug.In this type of design is carried out without the four-cycle timing.The rotary internal combustion engine can be used cheap fuel.Also, it is practically creates vibrations, cheaper and more reliable to manufacture than the piston heat engines.
3. rocket and jet engines heat.The essence of these devices is that the thrust created not by a screw, and by discharging the engine exhaust gases.Can create thrust in space without air.There are solid, liquid and hybrid).
And the last subspecies - a turboprop heat engines.Creation of energy is due to the screw and by the impact of exhaust gases.
