As an expert in thermodynamics, I can provide a comprehensive explanation regarding the behavior of entropy in an irreversible cyclic process. Entropy is a fundamental concept in the field of thermodynamics, often described as a measure of the disorder or randomness of a system. It is a state function, meaning its value depends only on the current state of the system and not on the path taken to reach that state.

In a cyclic process, a system undergoes a series of changes and then returns to its initial state. For a reversible process, which is an idealized concept where no energy is lost to the surroundings, the entropy change of the system over one complete cycle is indeed zero. This is because the system is returned to its exact initial state, and there is no net increase or decrease in the disorder of the system.

However, when we consider an irreversible process, the situation is different. Irreversibility implies that some energy is dissipated as heat to the surroundings, and this energy cannot be completely recovered to return the system to its initial state without additional work. In such cases, the entropy of the system does not return to its original value. Instead, there is a net increase in the entropy of the system.

The key point to understand here is that while the entropy change of the system in a cyclic process is zero for a reversible process, for an irreversible process, the entropy of the system increases. This is because the system does not return to its exact initial state due to the energy lost to the surroundings.

Moreover, the entropy generation is a critical concept in irreversible processes. Entropy generation occurs due to irreversibilities such as friction, heat conduction, and other dissipative phenomena. It represents the increase in the total entropy of the universe, which includes the system and its surroundings. According to the second law of thermodynamics, the total entropy of the universe always increases for any spontaneous process, and this is certainly true for irreversible processes.

In summary, while the entropy change of the system in a reversible cyclic process is zero, in an irreversible cyclic process, the system's entropy increases due to irreversibilities. The entropy generation is the increase in the entropy of the universe, which is always positive for irreversible processes, reflecting the second law of thermodynamics.

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The entropy change of the system (device) for a cyclic process is always zero whether it is a reversible or an irreversible one, because entropy is a property (point function). Also, for any reversible process, the entropy change of the universe is zero. ... the entropy generation(only occur for irreversible).read more >>