Daikin has announced an extension to its DZ oil-free centrifugal chiller portfolio, with the introduction of three new compressors in larger sizes.
Providing extra capacity, the new compressors are said to offer the flexibility to meet larger or more complex requirements including dry cooler and cooling tower applications.
The latest additions extend the capacity range on R134a models from 320kW to 2173kW and on R1234ze models from 227kW to 1415kW.
The new chillers are available with a standard or optional economized circuit in hot gas bypass or and heat pump versions.
The hot gas bypass (HGBP) version is said to reduce compressor cycling, stabilizing chilled water temperatures at very low loads. HGBP feeds discharge gas directly into the evaporator when the system load falls below 10% compressor capacity. This hot gas provides a stable refrigerant flow and keeps the chiller from short cycling under reduced load conditions, combined with high lift. It is also said to reduce surge potential on heat pump mode units.
The heat pump version includes pursuit mode with reversibility on the water side. A dedicated switch installed on the unit electrical panel allows selection of cooling or heating mode. The addition of a communication card enables this operation to be managed by BMS. This variant includes HGBP and additional insulation of 20mm on the condenser as standard.―Cooling Post