Thermodynamic Systems and Surroundings

Thermodynamics includes the study of different systems. The system in thermodynamics is not anything more than the collection of matter which is being study. A system could be the water inside one side of a heat exchanger, the fluid within a length of pipe, or the whole lubricating oil system for a diesel engine. Establishing the boundary to resolve a thermodynamic problem for a system will based  on  what  information  is  known  regarding  the  system  and  what  question  is  inquired  regarding  the system.

Everything exterior to the system is termed as the thermodynamic surroundings and the system is estranged from the surroundings by the system boundaries. Such boundaries might either be fixed or changeable. In many situations, a thermodynamic analysis should be made of a device, like a heat exchanger, which includes a flow of mass into and/or out of the device. The process which is obeyed in such an analysis is to identify a control surface, like the heat exchanger tube walls. Mass, and also heat and work (and momentum), might flow across the control surface.