| Features and
Benefits 
Cutaway view of Trane's electronic
expansion valve.
Electronic Expansion Valve
When coupled with Trane’s Adaptive Control™
microprocessor, our electronic expansion valve significantly improves part-load
performance of the Series R chiller by minimizing superheat in the evaporator and allowing
the chiller to run at reduced condensing temperatures. Chillers which use conventional
TXV’s must run at higher head pressures and consume more power than necessary at
part-loads. Additionally, the electronic expansion valve and its controls allow much
better stability and control over dynamic load and head changes. Under these conditions a
conventional TXV may never achieve control stability and extended periods of TXV
"hunting" and liquid slugging are common.
Capacity Control and Load Matching
Infinitely variable compressor modulation allows the
compressor capacity to exactly match the building cooling load. Reciprocating chillers
that rely on stepped capacity control must run at a capacity equal to or greater than the
load. Much of this excess capacity is lost because overcooling goes toward building latent
heat removal, causing the building to be dried beyond normal comfort requirements. The
result is an increase in chiller energy costs, particularly at the part-load conditions at
which the chiller operates most of the time.
PID Chilled Water Setpoint Control Through Slide
Valve Modulation
Maintain Chilled Water Supply Within ±½ F Of
Setpoint
Reciprocating chillers that have step capacity control
typically can only maintain water temperature to around ± 2 F. With the air-cooled Series
R chiller, maintaining temperature control has never been so accurate.
Reduce Compressor Cycling
Modulating capacity control offers better compressor
reliability. Compressor cycling, typical of reciprocating compressors, will decrease
compressor component life. Parts like motors and valves do not stand up well to excessive
compressor cycling. |
