9
pressure transducer, low pressure transducer, compressor’s inlet and outlet temperature sensors, thermal protection device for
fan motors, water side water flow switch to protect the evaporator, high pressure HP flow switch.
5.10
HYDRAULIC CIRCUIT
The heap pump chillers of i-HP series are supplied with an integrated hydronic kit including: plate heat exchanger, a pressure
gauges at the inlet and outlet of the heat exchanger for evaluating the load losses, service valve and flow switch for protection,
automatic air release valve and safety valve (6 bar) to be connected to the collection system. The version with an integrated
modulating type circulator pump adopting a brushless motor with high efficiency
(EEI≤0,23)
, suitable for the utilization of chilled
water and directly managed by the controller on board.
5.11
FAN SPEED CONTROL
This type of regulation, performed by the microprocessor, is necessary for optimizing the evaporation/condensation pressure
during summer/winter operation in order to allow the correct operation of the appliance.
5.12
ENHANCED VAPOUR INJECTION (EVI) TECNOLOGY
The heat pumps of
HPE
LT series are equipped with scroll compressors with vapor
injection (EVI technology) provide maximum efficiency regarding the standard units
with scroll compressors.
The EVI technology consists of injecting the refrigerant vapour at the intermediate
stage of the compression process which can significantly increase the capacity and
the efficiency of the compressor.
Each scroll compressor installed in the heat pumps of the series i-HP-LT is
comparable to a two-stage compressor but with an intermediate stage of cooling
the refrigerant.
The diagram shows the main stages of the refrigeration cycle of the unit with EVI
technology. The stage of high pressure is consisting of the extraction of a part of
the liquid refrigerant coming out of the condenser and then expands through an
injection valve, in a heat exchanger which functions as a sub-cooler.
The generated superheated vapour is then injected into the E.V.I. compressor in
the middle of the compression cycle (through a special pipe inside the compressor
itself).
The additional sub-cooling of the liquid thus obtained could greatly increase the
capacity of the evaporator.
A higher ratio between the condensation and evaporation pressures will
significantly increase the performance of this system with respect to all the
traditional technologies of gas compression.
This system allows the air/water heat pump of the series i-HP-LT to generate hot
water up to 60°C and capable of operating in temperatures up to -25°C.
