We were discussing “Carnot cycle and its efficiency” and also we have seen the “Carnot theorem and its explanation” in our previous post. We have also seen the concept of “corollary of Carnot’s theorem” in our recent post.

Today we will see here the efficiency of a reversible heat engine.
As we have already discussed the “concept of heat engine in thermodynamics, where we have defined that heat engine is basically defined as a device which will be operated in a thermodynamic cycle and will convert the heat energy or thermal energy in to mechanical energy.

Let us see one reversible heat engine, as displayed in following figure, which is receiving heat energy from higher temperature thermal reservoir at temperature T1 and rejecting heat energy to lower temperature thermal reservoir and simultaneously reversible heat engine is producing here the work energy W.

### Let us see the efficiency of reversible heat engine

Let us analyze the above formula of efficiency of reversible heat engine

Efficiency of any reversible heat engine working between two thermal energy reservoirs will never depend over the nature, type or quantity of working fluid but also it will be only dependent on the temperature of the both thermal reservoir.

If T2 decreases and T1 increases, we can easily conclude from above expression that efficiency of the reversible heat engine will increase.

We can also conclude here that T2 will be always greater than zero and positive because efficiency of a reversible heat engine will always be less than the unity.

T2: Temperature of cold thermal reservoir or lower temperature reservoir
T1: Temperature of hot thermal reservoir or higher temperature reservoir

Do you have any suggestions? Please write in comment box.
We will see another topic i.e. "Concept of internal energy in thermodynamics" and in our next post in the category of thermal engineering.

### Reference:

Engineering thermodynamics by P. K. Nag