Centrifugal chillers: new developments

New developments regarding centrifugal chillers include the world’s first production-scale chiller using water as a refrigerant and the world’s first photovoltaic direct driven inverter centrifugal chiller.
Centrifugal chillers are often used to air condition large structures such as office buildings and factories.
A variety of energy-saving technologies have been commercialized including oil-free magnetic bearings that reduce mechanical loss, large-capacity DC motors that improve full-load and part load efficiency, and high-performance aerodynamic impellers.
Market demand for magnetic-bearing centrifugal chillers is expanding sharply in the US, China, Europe and Australia, especially for data center cooling.
New developments can be noted:


. During CHILLVENTA, Efficient Energy, a German-based manufacturer, launched eChiller which it claims to be the world’s first production-scale chiller using water as a refrigerant.

Initially available as a 45 kW unit, Efficient Energy asserts it could save up to 50% over conventional chillers in its class. The key to using water as refrigerant is a patent micro-turbined centrifugal compressor which rotates at up to 90,000 rpm to increase pressure and therefore temperature in the fraction of water leaving the evaporator. The resulting steam is condensed directly into the remaining cool water flow.

Use of infinitely variable oil-free turbo compressors enable the eChiller’s cooling capacity to be adjusted continuously from 10 to 100%, while an intelligently controlled refrigerant circuit enables efficient modulation in response to changes in the ambient temperature.


. At the 2014 China Refrigeration Exhibition, Gree debuted the world’s first photovoltaic direct driven inverter centrifugal chiller. It has a cooling capacity ranging from 900 to 3,500 kW.
 
The Gree 15,000 m2 office building in Zhuai, China, which uses such a 400 kW chiller operates eight hours per day from April to October. Power output from solar energy reaches 340 kW, saving an annual total of 571,200 kWh in electricity.

JARN, November 25, 2014
http://goo.gl/rRNtnq