Mitsubishi Electric Y Series Manual page 102

102
For R2/WR2-Series (R2)
The secret of CITY MULTI heat recovery
systems lies in the
BC Controller
The BC controller houses a liquid/gas separator, allowing
the outdoor/heat source unit to deliver a mixture (2-phase)
of hot gas for heating and liquid for cooling, all through the
same pipe. The three pipe system allocates a pipe to each
of these phases. When this mixture arrives at the BC
controller, it is separated, and the correct phase is delivered
to each indoor unit according to the individual requirement for
either heating or cooling.
1
High pressure and low pressure
decides the compressor frequency,
the mode of heat exchange, and
controls the amount of heat exchange.
Heat source unit Outdoor unit
• Total heat recovery operation
Outdoor/heat source unit
High pressure liquid refrigerant from indoor
units in heating mode is delivered to indoor
units in cooling mode.
Gas-liquid 2-phase refrigerant from the outdoor/heat source
unit is separated into gas refrigerant and liquid refrigerant
by a gas-liquid separator in the BC controller.
Gas
High pressure refrigerant
gas-liquid
Gas
2-phase
refrigerant
refrigerant
Heating 25°C
2
R2/WR2 Refrigerant Circuit
The BC controller delivers refrigerant to
BC controller
each indoor unit in accordance with the
operation mode of each indoor unit.
Liquid
refrigerant
Liquid
refrigerant
Indoor unit
Heating 26°C Cooling 22°C Cooling 24°C
3
The refrigerant flow is adjusted
according to the temperature
difference between the inlet and
outlet.
Demands for cooling/heating are met flexibly
Heating mode/gas refrigerant
Cooling mode/liquid refrigerant
High pressure gas-liquid 2-phase refrigerant