If an internal combustion engine is a "heat engine", why is the cooling effect of the cooling liquid limited by a thermostat? Surely the lower the coolant temperature (exit temperature), the more efficient the engine.
2007-06-29 07:28:54 · 2 answers · asked by Poor one 6 in Science & Mathematics ➔ Physics
The coolant is not there to provide an analogy to the condenser in a generating turbine, for example. It's there to stop the engine from overheating. It closes at low temperature to allow the engine to warm up to its operating temperature, which is mainly dictated by the lubricant and materials used in the engine. The actual heat-dumping part of the cycle is in the hot exhaust; the environment is a part of the heat engine itself.
2007-06-29 07:33:28 · answer #1 · answered by poorcocoboiboi 6 · 1⤊ 0⤋
An internal combustion engine is a heat engine, true.
The gas is compressed, burned, then expands, doing work on the piston. During compression and burning, the gas heats up. As it does work on the piston, the gas cools down. Finally, the hot exhaust gas is ejected into the environment.
There is no coolant in the basic model of the internal combustion engine. The efficiency is determined by the compression ratio of the engine.
2007-06-29 07:34:44 · answer #2 · answered by lithiumdeuteride 7 · 0⤊ 0⤋