We were discussing the concept of reversible and irreversible thermodynamic process in our previous post, where we have discussed the basics of a reversible and irreversible thermodynamics process with the help of few examples too. We have also seen the concept of enthalpy and specific heat in our previous posts.

Today we will see here the concept of reversible cycle, reversible heat engine and also reversible heat pump with the help of this post.

### So let us see first reversible cycle

As we have already discussed that any thermodynamic process or series of processes will be termed as thermodynamic cycle, when thermodynamic system undergoes through such changes of states that initial state is similar with final state.

If each process of a thermodynamic cycle is a reversible process then that thermodynamic cycle will be termed as reversible cycle. We must note it here that if any process of thermodynamic cycle will be irreversible then that thermodynamic cycle will not be termed as reversible cycle.
Let us see here the following figure,
Above figure indicates the thermodynamic cycle drawn between Pressure and volume. System starts with condition 1 and reaches at condition 2 by following constant pressure process. Again system reaches condition 3 by following constant volume process and finally reaches to initial condition 1. So we may see here that final condition and initial condition of the system are similar even system has completed processes 1 to 2 and 2 to 3 and finally 3 to 1.

This cycle will be termed as thermodynamic cycle and if process such as 1 to 2 process and 2 to 3 process and finally 3 to 1 process are all reversible process then this cycle will be termed as thermodynamic reversible cycle.

### Now we will see here reversible heat engine and reversible heat pump

We have already discussed the concept of heat engine and heat pump in our previous post. Now we can define the concept of reversible heat engine and reversible heat pump.

A heat engine operating on a reversible cycle will be termed as reversible heat engine and similarly a heat pump operating on a reversible cycle will be termed as reversible heat pump.

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

#### Reference:

Engineering thermodynamics by P. K. Nag
Basic thermodynamics by Prof. S.K. Som