period two
Chilled-Water System Design
notes
Multiple-Chiller Systems
▲Redundancy
▲Part-load efficiency
Figure 40
Multiple-chiller systems are more common than single-chiller systems for the same reason that most commercial airplanes have more than one engine— redundancy provides reliability. Additionally, because cooling loads typically vary widely, multiple-chiller systems can often operate with less than the full number of chillers. During these part-load periods, the system saves the energy required to operate the additional chillers, pumps, and, in water-cooled systems, cooling tower fans.
There are several configurations used to connect multiple chillers in these systems. Some of these configurations work well, others do not. Next, we will look at the most-commonly-used system configurations, including their advantages and drawbacks.
