During the past few years a new technology, Stirling cycle, has begun to
receive considerable amount of attention in the search for ever more
efficient technologies.
During the past few years a new technology, Stirling cycle, has begun to
receive considerable amount of attention in the search for ever more
efficient technologies.
Among household appliances, domestic refrigerators and freezers are the
number one consumers of electricity. In the European Community fridges
and frezers account for 24 per cent of domestic energy demand, or 6 per
cent of the total electricity demand.
Energy consumption of an average refrigerator with separate freezer
compartment ranges from 600 kWh/year in Europe, to 1310 kWh/year in the
USA. An average refrigerator without freezer compartment consumes in
Europe about 350 kWh/year.
All household fridges and freezers in the world have one thing in
common: the Rankine evaporation cooling system (recognizable by the
black compressor pot & condenser). The Rankine cycle cooling system is
the true barrier to super energy efficient cooling and freezing.
The Stirling cycle cooler is a free piston, linear motor driven device.
The internal runnnig surfaces are supported by gas bearing, so no
contact wear takes place. The entire unit is hermetically sealed. It is
capable of continuous modulation and of maintaining high efficiencies
down to very low lifts. This means that it adopts easily to cooling
needs and keeps performing with high efficiency even at low demand.
The performance of the Stirling cycle cooling motor is on average about
two to three times more efficient than the Rankine machine. According
to Sunpower , the developers of Stirling cycle, the Stirling cycle
compressor is a "drop-in" replacement for conventional compressors in
domestic and commercial refrigerators, air conditioners and heat pumps.
An additional attractive feature of the Stirling cycle
refrigerator/freezer is that it can be powered by a solar power.
Stirling cycle refrigerators are not yet available on a mass production
level. They may well represent the future direction towards a super
efficient, solar powered refrigerator.
