A system (27) for reducing the temperature of cooling oil for a power
transformer
(12) includes a heat exchanger (44) interposed in the cooling oil
system. The heat exchanger (44) relies upon a liquid-to-liquid exchange
of heat from the heated oil to a coolant flowing through the heat exchanger. In
one embodiment, the coolant provided to the heat exchanger is obtained from an
absorption chiller (65). Heat energy is provided to the chiller (65)
from a heat storage device (80). In a specific embodiment, the heat storage
source (80) can be a phase change material device. In a preferred cooling
system, a programmable controller (55) determines the activation and operation
of the system. The controller (55) can sense transformer or cooling oil
temperature to trigger activation. In a preferred embodiment, the controller (55)
compares a current temperature history against a temperature profile to anticipate
increased cooling requirements. In certain embodiment, excess, off-peak or waste
heat from the transformer (12) itself is provided to the heat storage device
(80) or to the phase change heat exchanger.
