ABS Provides, Руководство по эксплуатации, Страница: 6 / 32

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3. Introduction
INTRODUCTION
3.2 CONDENSER
The main application of PROVIDES condensers is the condensation of the refrigerant that comes out from
the compressor (and from evaporator) in order to make it liquid and ready to begin a new cycle. Through
the thermal cycle of condensation the refrigerant (gas), intended
as
the primary fluid, transfers heat to the
secondary fluid (generally water) and condenses.
Generally primary fluid gets in the condenser from the top of the shell and it is totally distributed around the
tube bundle. The secondary fluid flows into the tubes of the tube bundle.
On request it is possible to produce totally or partially heat recovery units for sanitary use.
The standard construction materials of PROVIDES condensers consists in: copper for tube bundle; cast iron
or carbon steel for the header; carbon steel for tubesheets, shell, baffles, hydraulic connections and support
brackets.
Refrigerant connections are generally made of copper.
It is possible to supply carbon steel gas side connections.
On request other materials can be used.
3.1 FLOODED EVAPORATOR
The main application of PROVIDES flooded heat exchangers (from here simply “Flooded EV”) is into HVAC
plants, in which through the thermal cycle of condensation and evaporation
of
the refrigerant, intended as
the primary fluid, transfers heat to the secondary fluid (generally water) condensing or evaporating itself.
Primary fluid gets in the shell of the flooded and
is
totally distributed around the tube bundle. The
secondary fluid flows into the tubes of the tube bundle.
The standard construction materials of PROVIDES Flooded EV consist in: copper for tube bundle and carbon
steel for header, tubesheets, shell, baffles, hydraulic and refrigerant connections and support brackets.
On request other materials can be used.
3.3 Refrigerants
It is possible to use HCFC, HFO, HFC, NH3 and propane and others
,
provided they are compatible with
construction materials and certification. Heat exchanger performance depends on the type of refrigerant, so
different refrigerants will yield different capacities under the same conditions.
3.4 Secondary fluids
Heat exchanger’s performance depends on the type of secondary fluid as well.
It’s necessary to check water quality in order to avoid scales or acid etching that may compromise the tube
bundle integrity.
For flooded evaporator, if the evaporation temperature or water temperatures are less than 0°C an antifreeze
solution must be used.
Most common solutions are ethylene or propylene glycol type.
Other types of solutions can be used
,
unless
not
compatible with construction materials of the heat
exchangers. Be advised that glycol solution’s viscosity changes as temperature changes, with a consequence
of an increase of pressure drop as temperature decreases.