What does the equation h=Δu + pv represent in boiler systems?

The equation h = Δu + pv is referred to in thermodynamics and specifically in the context of boiler systems, where h represents enthalpy, Δu represents the change in internal energy, p is pressure, and v is specific volume. This equation is significant because it relates the enthalpy of a system to its internal energy and the work done by the system due to volume changes under pressure.

In boiler systems, understanding the relationship between heat, internal energy, and pressure-volume work is crucial for evaluating the energy transformations that occur during phase changes, such as when water turns into steam. The internal energy (Δu) accounts for the energy associated with the molecules of the substance, while the term pv (pressure multiplied by specific volume) accounts for energy associated with the system's volume under pressure. Together, these components make up the total enthalpy, which is a key parameter for designing and analyzing boiler operations.

By focusing on this relationship, engineers can ensure efficient energy transfer and effective steam generation, which are vital for the operation of power plants and various industrial processes. This conceptual framework is foundational for anyone studying power engineering and helps in performing calculations related to energy efficiency and thermodynamic cycles.