Abstract
When the fundamental thermodynamic balance equations (mass,
energy, and momentum) are used to describe the processes in a
simple refrigeration system, then one finds that the resulting
equation system will have a degree of freedom equal to one.
Further investigations reveal that it is the equation constraining
the total charge of refrigerant in the system, which is missing.In
traditional mathematical modelling of a refrigeration
cycle/system, the influence from the total charge of refrigerant
on the system behaviour is normally not modelled explicitly.
Instead, parameters such as superheat and subcooling are
introduced. Since the degree of freedom was equal to one, using
both the superheat and subcooling require that one of the
fundamental equations must be omitted from the equation system.The
main purpose of the paper is to clarify the relation between the
fundamental balance equations and the before mentioned parameters.
In doing so, a systematic use of control volumes for modelling a
refrigeration system is outlined.
| Original language | English |
|---|---|
| Title of host publication | Using fundamental equations to describe basic phenomena |
| Publication date | 1999 |
| Publication status | Published - 1999 |
| Event | 20th International Congress of Refrigeration - Sydney, Australia Duration: 19 Sept 1999 → 24 Sept 1999 |
Conference
| Conference | 20th International Congress of Refrigeration |
|---|---|
| Country/Territory | Australia |
| City | Sydney |
| Period | 19/09/1999 → 24/09/1999 |