Perating Conditions; Refrigerant And Lubricants - Danfoss MLZ Selection & Application Manuallines

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PPLICATION GUIDELINES

Refrigerant and lubricants

General information
R22
R134a
R404A
R507
PVE
Alkylbenzene oil
20
O

PERATING CONDITIONS

The scroll compressor application range is influ-
enced by several parameters which need to be
monitored for a safe and reliable operation.
These parameters and the main recommenda-
tions for good practice and safety devices are ex-
plained hereunder.
When choosing a refrigerant, different aspects
must be taken into consideration:
• Legislation (now and in the future)
• Safety
• Application envelope in relation to expected
running conditions
• Compressor capacity and efficiency
• Compressor manufacturer recommendations &
guidelines
R22 is an HCFC refrigerant and is still a wide use to-
day. It has a low ODP (Ozone Depletion Potential)
and therefore it will be phased out in the future.
Check local legislation.
Refrigerant R134a is an HFC refrigerant. R134a has
zero ozone depletion potential (ODP = 0) and is
commonly accepted as the best R12 alternative.
R134a is a pure refrigerant and has zero tempera-
R404A is an HFC refrigerant. R404A has zero ozone
depletion potential (ODP = 0). R404A is especially
suitable for low evaporating temperature applica-
tions but it can also be applied to medium evapo-
rating temperature applications. R404A is a mix-
R507 is an HFC refrigerant with properties com-
parable to R404A. R507 has no ozone depletion
potential (ODP = 0). As with R404A, R507 is par-
ticularly suitable for low evaporating temperature
Polyvinyl ether (PVE) is an innovative refrigeration
lubricant for HFC refrigerant systems. PVE is as hy-
groscopic as existing polyolester lubricants (POE),
but PVE doesn't chemically react with water; no
acids are formed and compressor evacuation is
easier.
Alkylbenzene oil can be applied in systems using
HCFC refrigerants (R22). Compared to a mineral oil
it provides distinct advantages: excellent miscibil-
ity, excellent thermal stability, compatibility with
mineral oils and constant quality.
FRCC.PC.016.A1.22
• Refrigerant and lubricants
• Motor supply
• Compressor ambient temperature
• Application envelope (evaporating tempera-
ture, condensing temperature, return gas tem-
perature)
Additional points could influence the final choice:
• Environmental considerations
• Standardisation of refrigerants and lubricants
• Refrigerant cost
• Refrigerant availability
When R22 is applied in refrigeration applications it
can lead to high discharge temperature. Carefully
check all other parameters that can influence the
discharge temperature.
ture glide. For applications with high evaporating
and high condensing temperatures, R134a is the
ideal choice.
ture and has a very small temperature glide, and
therefore must be charged in its liquid phase, but
for most other aspects this small glide can be ne-
glected. Because of the small glide, R404A is often
called a near-azeotropic mixture.
applications but it can also be used for medium
evaporating temperature applications. R507 is an
azeotropic mixture with no temperature glide.
The compressor technology applied in MLZ com-
pressors in combination with PVE lubricant pro-
vides the best possible result in terms of reliability
and compressor lifetime.
The PVE lubricant is compatible with R22 which
makes the MLZ compressors a very versatile multi-
refrigerant solution.
MLM series compressors are charged with Alkyl-
benzene oil and herewith offer an economically
interesting alternative to the MLZ series in regions
where R22 is still the predominant refrigerant.
Note however that MLM compressors can not be
used with HFC refrigerants.