Rotary 2-Stage CO₂ Compressor

Description:

Sanyo has been producing hermetic rotary compressors for transcritical CO₂ cycles since 2001. Main applications of its 2-stage compressor are heat pump water heaters and vending machines.


Basic specifications:

• Two stage compression in one compressor
• Pressure drop High Pressure (HP) side (bar/m): 0.04
• Number of Cylinders: 2
• Internal intermediate pressure structure
• Variable speed type (Inverter drive required) and Single Speed type are available
• Weight: around 9kg (depends on the capacity)
   

Unique features of the CO₂ rotary 2-stage compression compressor:

• Resistant to high working pressure: The internal intermediate pressure structure makes it easy to design the shell.

• Resistant to large pressure difference: The 2-stage compression makes it possible to disperse the differential pressure and compression load.

• Increased efficiency: Leakage is reduced by the 2-stage compression, the dimensions of the compression mechanism are optimized, and a high-efficiency DC brushless motor is incorporated.

• Compact size and light weight: The shell has thinner walls due to the internal intermediate pressure structure, and a compact concentrated winding motor is provided.

• Minimized noise and vibration levels: Equalization of a torque on that of twin rotary compressor is achieved thanks to the compression mechanism's 2-cylinder structure in which the two cylinders face each other at 180 degrees.

• Just right for hot water heaters in cold climates: The internal intermediate pressure structure enables discharging at a higher temperature than with regular rotary compressors. Users can select the volume ratio (displacement volume ratio between the first and second stages) that suits the intended application, which makes the compressors just right for use in winter and for water heaters in cold climates.

Background:


In 2010, Panasonic acquired Sanyo Electric and since then continues Sanyo's expertise in CO₂ refrigeration and heat pump technology. The former Sanyo had developed the world's first CO₂ rotary 2-stage compression compressor that uses the CO₂ found in the natural world as a refrigerant.