TABLE OF CONTENTS "Every man has a right to his opinion, but no man has a right to be wrong in his facts."
- Bernard Baruch
Internal entropy production typically dominates the thermodynamic performance of real chillers. For typical reciprocating chillers, around 60% of the total losses derive from internal dissipation. The corresponding figure for common absorption chillers is over 50%. One can analyze the measurements reported in Chapters 6 10 to confirm that the 50 60% figures are the rule rather than the exception. The quasi-empirical models of Chapter 10 are predicated on internal losses governing chiller COP. The accuracy of the model's predictive and diagnostic capabilities is difficult to account for other than by the dominance of internal losses.
As sample exercises for mechanical chillers, start with the analytic chiller performance equations of Chapter 5. Plug in realistic values of coolant temperatures, cooling rates and chiller characteristic parameters. Now examine the relative contribution of each term to COP. Internal losses are always significant, and typically the dominant factor ( e.g., Tutorial 6.1).
Any chiller model that summarily excludes internal dissipation clearly omits more than half the physics of the problem; it cannot offer predictions that correspond to reality. Hence it is surprising to discover the large number of journal articles that propose endoreversible models for the behavior of real chillers. (Rather than provide an extensive list of these articles here, we refer the reader to the papers where the shortcomings of endoreversible...
