What is meant by the term "latent heat"?

Latent heat refers to the amount of energy absorbed or released by a substance during a phase change, such as when a solid turns to liquid or a liquid turns to gas, without a change in temperature. This concept is crucial in understanding various thermodynamic processes, particularly in power engineering, where phase changes often play a significant role in heat transfer and energy conversion.

When a substance undergoes a phase change, its temperature remains constant while the energy is either absorbed or released. For example, when ice melts into water, it absorbs latent heat; conversely, when steam condenses into water, it releases latent heat. This energy is hidden or "latent" because it does not result in a temperature change despite the energy transfer.

Understanding latent heat is essential for engineers working with heat exchangers, boilers, and refrigeration systems, as these systems often rely on the latent heat of water and other substances to operate efficiently and effectively.