Page 142 - Handbook of Energy Engineering Calculations

to drive the chiller, a heat exchanger for extracting heat from the inlet air, and
a heat-rejection system.

FIGURE 9 Inlet-air chilling using either centrifugal or absorption-

type chillers boosts the achievable mass flow and power output during
warm weather. (Power.)

A mechanical chilling system. Case 2, Table 1, is based on a compressor-
driven unit. The compressor is the most expensive part of the system and

consumes a significant amount of energy. In general, chillers rated above 12-
million Btu/h (3.5 MW) (1000 tons of refrigeration) (3500 kW) employ
centrifugal compressors. Units smaller than this may use either screw-type or
reciprocating compressors. Overall, compressor-based chillers are highly

reliable and can handle rapid load changes without difficulty.