One
of the most critical areas of air to air and air to water heat pump
application is the proper control of liquid refrigerant under low
ambient heating conditions. System design must maintain a delicate
balance between sufficient flooding to adequately cool the compressor,
while avoiding excessive flooding which would adversely affect lubrication.
When coil defrost is required, the compressor is exposed to sudden
surges of liquid refrigerant and oil that can create extreme stresses
in the compressor. Both laboratory testing and field experience
indicate that a properly designed suction accumulator can provide
excellent protection against both potential hazards.
The accumulator can act as a receiver during the heating cycle when
system imbalance or an overcharge from field service result in excessive
liquid refrigerant in the system, storing the refrigerant until
needed and feeding it back to the compressor at an acceptable rate.
This prevents damage to reed valves, pistons, rods and crankshaft.
Major movements of refrigerant take place at the initiation and
termination of defrost cycle, and while it is not necessary or even
desirable to stop this movement, it is essential that the rate at
which the liquid refrigerant is fed back to the compressor be controlled.
Again, the accumulator can effectively maintain the crankcase temperature
within acceptable limits.
The
“U" tube accumulator design is a result of extensive
testing plus detailed investigation of the various accumulators
currently available. It takes into account all of the requirements
essential for heat pump applications, including safe holding volume
(relative to the system's total charge), protected flow control
for positive refrigerant and oil return, and minimum pressure drop
across the accumulator.
accumulators feature on inlet deflector that blends refrigerant
flow to prevent the internal splashing and aid in the collection
of refrigerant oil in the bottom connection of the accumulator.
It assures adequate oil return of refrigerant vapour only and prevents
compressor failure due to liquid refrigerant entering the compressor.
Design Feature
• Solid Copper connections made from seamless (99.90%) copper
tube which has a very high burst strength.
• 'U' tube design for maximum flow of refrigerant and minimum
entrapment.
• Inlet flow director guides refrigerant towards wall for
smooth tangential flow and gradual expansion. • 'U' tube entrance is positioned behind the inlet
flow director to prevent unwanted liquid refrigerant from entering
and damaging compressor.
• Metering ejector device that pick up liquid, vaporizes it
and returns it to the compressor. This prevent the liquid slugging
and controls oil return. It is particularly important on hot gas
defrost systems, heat pumps etc. where surges of liquid refrigeration
frequently go back down the suction line.
• Right Size Orifice 'U' tube design draw gaseous refrigerant
off to the top of the vessel. At the bottom of the 'U' tube an orifices
picks up a small amount of oil and liquid refrigerant and meters
it back with the gaseous refrigerant. The small amount of liquid
refrigerant will boil off in the suction line. The oil will be carried
with the gaseous refrigerant back to the compressor.
• A vent hole at the top of the accumulator 'U' - tube outlet
act as a vacuum break to prevent an accumulator that has flooded
during on off cycle from slugging upon start up of the system.
• Protective screen and orifice assembly on U - tube protects
against foreign particles and contaminants affecting metering function.
• Fitting and U - tube are matched to accumulator holding
capacity and total system charges for minimum pressure drop and
maximum refrigerant flow.
• It also acts as a suction muffler.
• Designed to operate in the range of +40º F to -40º
F evaporator temperature.
• Tested for 1775 PSIG. minimum burst pressure and 300 PSIG
max. working pressure (20.68 bar)
• 430ºF Fusible plug on larger diameter units i.e. above
3" diameter (under development)
• High Brazing strength on inlet and outlet connection helps
to stand flame temperature while fixing into the system. (Please
follow brazing instruction)
• Bottom mounting stud are not welded or hand brazed but projection
welded thus avoiding chances of leakage and also give neat
look.
• Leak testing - Three stage high pressure leak testing done
with dry N2. (a) Before assembling, i.e. on inlet and outlet tube
connection. (b) After Co2 welding (c) After
painting (Accumulator can also be shipped with an internal atmospheric
pressure of dry N2 ranging in pressure from 12 to 30 PSIG. This
prevents moisture from entering the accumulator in storage and presence
of pressure also confirms no leaks in particular piece at the time
of fitting.
• Accumulator inlet and outlet is designated on the label.
• For use with CFCS, HCFS, HFCS and lubricant combination
that go with it.
Other Feature and Technical Tips :
• OEM approved design.
• Vertical mounting only-Install the accumulator vertically
on the same level and adjacent to the compressor in order to minimize
the suction line length between Accumulator and Compressor. Connect
the suction line from the evaporator to the inlet of the Accumulator.
Connect the outlet of the Accumulator to the suction line of the
compressor.
• On systems with a reversing valve and on heat pump systems,
the Accumulators should be installed between the compressor and
the reversing valve. The pump down cycle should precede all compressor
shut downs.
•
offers standard accumulator models designed for application on heat
pump and refrigeration systems as per customers drawing and specification.
• Liquid refrigerant holding requirements of suction line
accumulator may vary in application because of the diversity in
heat pump systems, and other refrigeration system. Accumulator capacity
selection should be determined by actual testing. Double check the
sizing of the Accumulator insuring that the tonnage is not above
the maximum capacity, and that the accumulator can hold at least
50% of the system charge.
“U" tube accumulator design is a result of extensive
testing plus detailed investigation of the various accumulators
currently available. It takes into account all of the requirements
essential for heat pump applications, including safe holding volume
(relative to the system's total charge), protected flow control
for positive refrigerant and oil return, and minimum pressure drop
across the accumulator.