Stream Availability - The availability of a fluid stream. The mass or region outside of a system. Surroundings Work - The work done by or against the surroundings during a process. System - A quantity of matter or a region in space chosen for study. Thermal Efficiency - Thermal efficiency is the fraction of the heat input that is converted to net work output.
Thermal efficiency is a measure of the performance of a heat engine.
Thermodynamic Temperature Scale - A temperature scale that is independent of the properties of the substances that are used to measure temperature. Thermodynamic Equilibrium - Occurs when the same temperature exists throughout the system. Third Law of Thermodynamics - States that the entropy of a pure crystalline substance at absolute zero temperature is zero. The pressure drop is often accompanied by a large drop in temperature. Throttling valves are often used in refrigeration and air-conditioning applications.