Local Equation of Enthalpy for Flow Systems According to the Balance Theory

The paper presents a generalised local equation of enthalpy for an open system, which has been transformed into a local equation of enthalpy for an open system. It has been assumed that the flow of an agent through a machine is fixed and that elementary heat created by friction in the machines interior equals an elementary work of friction and an elementary increase of technical work is equal to an elementary of indicated work. Internal and effective power of a rotor or piston flow machine have been established for the above assumptions. By assuming the effective power provided by the machine to be zero, we have obtained a balance equation which describes the work of a heat exchanger.