Mitsubishi Electric Y Series Manual page 164

TECHNOLOGY INTRODUCTION
164
Heat Inter-Changer (HIC) circuit
Y-Series EP R2-Series
Y-Series P R2-Series
The HIC circuit increases cooling efficiency. This technology raises the degree of supercooling, increasing both cooling
capacity and cooling efficiency.
The HIC circuit is installed before the point at which the high pressure liquid refrigerant, which passes through the heat
exchanger of the outdoor/heat source unit, flows into the indoor unit. The temperature of the liquid refrigerant, to which
heat is discharged from the outdoor/heat source unit heat exchanger, is further lowered before the refrigerant enters the
expansion valve, to allow the evaporator to absorb a large amount of heat and increase cooling efficiency.
HIC mechanism
Some of the high pressure liquid refrigerant that passes through the outdoor/heat source unit heat exchanger flows
directly into the indoor unit, and the rest passes through linear expansion valve (LEV) "C" to lower both the temperature
and pressure. The heat is exchanged between the low temperature, low pressure liquid refrigerant that passes through
LEV "C" and the moderate temperature liquid refrigerant from the outdoor/heat source unit heat exchanger. This further
lowers the temperature of the liquid refrigerant before it enters LEV "B." This heat exchange system uses a
"double-pipe" heat exchanger.
• HIC circuit diagram
*In case of Y-series
The evaporator absorbs
a large amount of heat
and increases the
cooling effect.
The refrigerant is
separated; some flows into
the indoor unit, and some
passes through LEV "C."
• HIC circuit effect: (Image using a Mollier diagram)
• HIC circuit
(Double-pipe heat exchanger)
A
Heat Inter-Changer (HIC) circuit
*In case of Y-series
EP WY-Series
P WR2-Series
Cooling operation
Indoor
HEX
LEV B A
LEV C
Subcool
Expansion
• Double-pipe heat exchanger cross section
(High-performance grooved pipe)
Low temperature, low
pressure liquid refrigerant
that passes through LEV
"C"
Outdoor
Accumulator
Compressor
HEX
LEV A
Heat
Inter-Changer (HIC)
Condensation
Compression
Evaporation
Current
New
w/ HIC circuit
w/o HIC circuit
Double-pipe heat exchanger
The double-pipe heat exchanger
exchanges the heat between the low
temperature, low pressure liquid
refrigerant that passes through LEV "C"
and the moderate temperature liquid
refrigerant from the outdoor unit heat
exchanger. This allows the refrigerant
to cool down to a lower temperature
when flowing through the indoor unit.
High pressure, moderate temperature liquid
refrigerant that passes through the outdoor
unit heat exchanger