What is the purpose of the design of heat engines and what are the two categories of heat engines?

A heat engine has two main objectives: supplying for process heat demand and generating power. Appropriate integration of a heat engine with the process provides the most energy efficient combination of these objectives.

Why is it a must for heat engines to have a heat sink?

We know from the second law of thermodynamics that 100\% conversion of heat to work is impossible hence a colder sink is necessary to allow a heat engine to work in the first place. Every engine utilizes a working fluid, that absorbs heat from the hot reservoir, Rh, expels waste heat, and does useful work.

Why does a heat engine need a temperature difference?

Making the temperature of the fluid inside the cylinder higher at the start of the cycle makes it more efficient; making the temperature lower at the opposite extreme of the cycle also makes it more efficient. In other words, a really efficient heat engine operates between the greatest possible temperature difference.

What is the purpose of heat engine?

In thermodynamics and engineering, a heat engine is a system that converts heat to mechanical energy, which can then be used to do mechanical work. It does this by bringing a working substance from a higher state temperature to a lower state temperature.

Why do we use heat engines?

Almost all of the energy that is harnessed for transportation and electricity comes from heat engines. Hot objects, even gases, have thermal energy that can be turned into something useful. Heat engines move energy from a hot place to a cold place and divert some of that energy into mechanical energy.

How does heat do work in heat engines?

In thermodynamics and engineering, a heat engine is a system that converts heat to mechanical energy, which can then be used to do mechanical work. It does this by bringing a working substance from a higher state temperature to a lower state temperature. Also, some energy is unusable because of friction and drag.

Why are heat engines not 100\% efficient?

A heat engine is considered to be 100\% efficient if only all the heat is converted into useful work or mechanical energy. Since heat engines cannot convert all the heat energy into mechanical energy, their efficiency can never be 100\%.