Different Parts of Heat Energy

In science, heat can be defined as a medium for transferring energy from one source to another. Heat energy is produced with the movement of atoms, ions, and molecules. Heat energy can move from one system to another due to the difference between the temperature of objects. This energy can be generated and transferred via a device known as a heat engine. 

Heat engines are machines or devices used to do useful work by converting heat into mechanical energy from the ignition of fuel, coal, wood, or other sources of energy. In other words, heat energy is produced through a heat engine which is then converted into another form of energy, such as mechanical energy or electrical energy via dynamo. 

What are the parts of a heat engine?

The heat engines consist of three different parts of heat energy. They are as follows:

Source or Heater

It is the major part of the heat engine. The primary function of the source is to keep up the unlimited thermal capacity, which allows the source to be stable even after maintaining or adding a significant quantity of heat. It is also referred to as a hot body since it has infinite heat capacity.

System or Working Object

In the system, heat mixes with other gas or air that is a working substance, and the system heats up. The working substance for steam engines is water, and for petrol vehicles, it is petrol. Working substance absorbs the heat and expands it. The heat made in the system can be used in machines to work.

Sink

The rest of the heat, left after the use, is sent to the sink in a cold reservoir. It is the same as the bike engine; the bike engine generates heat that makes the wheels move and the rest of the heat goes out through the silencer. The sink absorbs heat, as in the bike example, and the atmosphere air absorbs heat.

The efficiency of Heat Engine

The efficiency of a heat engine is vital because it shows how much work, i.e., usable, we get as an output from the heat engine when we utilise the same quantity of heat energy as input.

Efficiency of heat engine:

n = 1 – Q2Q1

And n is  WQ1

Where 

Q1 = work done in 1st cycle

Q2 = work done in 2nd cycle 

Example of efficiency of Heat Engine

Ques. In the Carnot engine, efficiency is 60% at hot reservoir temperature Q. For efficiency of 70%, what will be the temperature ratio of temperature of the sink (Q1) and  temperature of the hot reservoir(Q2)?

Ans. From the above formula:

The efficiency, n is  WQ1

n=1 – Q2Q1

where, Q2= temperature of the sink

and Q1= temperature of the hot reservoir

60100 = 1 – Q2Q1

Q2Q1 =0.4

⇒Q2 = 0.4Q1

Now, 70100 = 1 – Q2Q1

Q2Q1 =0.7

Conclusion

In the above article, we have discussed the heat energy and conversion of heat energy into mechanical energy in the heat engine to do useful work. We have also looked into the three major parts of a heat engine: the source, sink, working object, and the efficiency of a heat engine.