ABSTRACT
This chapter covers the ideas and concepts associated with thermodynamic systems. It considers the transfer of work, energy and power in and out of the system, using the non-flow and the steady flow energy equations, and discusses the idea of enthalpy and specific enthalpy of the working fluid in open systems. In the closed system there is, a closed or fixed boundary containing a fixed amount of the system working fluid, while only an exchange of heat and work energy may take place across the system boundaries. Heat entering a system is positive, work leaving a system is positive. Another way of expressing the same thing is to say that heat supplied to the system, or done on the system, is positive and that work output or work done by the system is also positive. In other words, the total energy entering a system is equal to the total energy leaving the system.
