TABLE OF CONTENTS "The essence of knowledge is, having it, to apply it; not having it, to confess your ignorance."
- Confucius
We devote our final chapter to
address the weak points and caveats of the chiller analyses advanced in earlier chapters; and
examine the rudiments of the operation and performance of examples of less conventional types of chillers, including relating them to the types of thermodynamic modeling we have been advocating.
The thermodynamic models developed and tested in this book adopt approximations that turn out to work well for the chillers we've examined and for most of the commercial chillers in use today. But they should not be used blindly in analyzing new devices and systems that differ noticeably from current common cooling machines.
One of our central assumptions has been that the rate of internal entropy production ? S int can be treated as constant for the operating ranges of practical interest. That appears to be a satisfactory approximation for most commercial mechanical and absorption chillers. This claim is borne out both directly by the measurement of chiller internal dissipation for reciprocating chillers, and indirectly by the evidence that models predicated on the constant- ? S int assumption provide excellent predictions of chiller behavior for centrifugal, reciprocating and absorption systems.
One reason for ? S int being nearly constant is a compensatory tendency. Consider the rate of internal dissipation (in kW K -1) as the product of the mass...
