Operating conditions
The scroll compressor application range is
influenced by several parameters which need to
be monitored for a safe and reliable operation.
These parameters and the main
recommendations for good practice and safety
devices are explained hereunder.
•
Refrigerant and lubricants
•
Motor supply
•
Compressor ambient temperature
•
Application envelope
(evaporating
temperature, condensing temperature, return
gas temperature).
General information
Refrigerant and
lubricants
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
Additional points could influence the final choice:
• Environmental considerations
• Standardisation of refrigerants and lubricants
• Refrigerant cost
• Refrigerant availability
R22
R407C
R22 is an HCFC refrigerant and is still a wide
use today. It has a low ODP (Ozone Depletion
Potential). Starting from 1st January 2010, the use
of virgin R22 refrigerant is no longer allowed in
the European Union. Refer to FRCC.EN.049 for R22
retrofit recommendations.
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.
R407C is an HFC refrigerant and has a zero ozone
depletion potential (ODP=0) R407C is a zeotropic
mixture and has a temperature glide of 7.4°C
but has a superior thermodynamic properties
compared to R22.
R404A
R507
POE oil
Mineral oil
R404A is an HFC refrigerant and has zero ozone
depletion potential (ODP = 0). R404A is especially
suitable for low evaporating temperature
applications but it can also be applied to medium
evaporating temperature applications. R404A is a
mixture 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
neglected. Because of the small glide, R404A is
often called a near-azeotropic mixture.
R507 is an HFC refrigerant with properties
comparable to R404A. R507 has no ozone
depletion potential (ODP = 0). As with R404A,
R507 is particularly suitable for low evaporating
temperature applications but it can also be
used for medium evaporating temperature
applications. R507 is an azeotropic mixture with
no temperature glide.
Mineral oil can be applied in system using HCFC's
refrigerant because it has a good miscibility
with HCFC and oil that leave the compressor
with refrigerant may not be trapped in lines or
exchangers. The chlorine contained in HCFC's
improves lubricity in bearings used with mineral
oil. Mineral oil has a very low hygroscopicity but
may chemically react with water and form acids.
Polyol Ester Oil (POE) is miscible with HFC's
(while mineral oil is not), but has to be evaluated
regarding lubricate ability in compressors.
POE oil has better thermal stability than
refrigerant mineral oil.
POE is more hygroscopic and also holds moisture
more tightly than mineral oil. It also chemically
react with water leading to acid and alcohol
formation.
R134a is an HFC refrigerant and has zero ozone
depletion potential (ODP = 0). R134a is a pure
refrigerant and has zero temperature glide. For
applications with high evaporating and high
condensing temperatures, R134a is the ideal
choice.
R513A is an HFO/HFC Blend, with similar
thermodynamic properties to the R134a. R513A
is an Azeotrope refrigerant with a negligible
glide. R513A has zero ozone depletion potential
(ODP=0) and a Global Warming Potential (AR5)
at 573
R134a
R513A
25
AB237986441643en-010801
Application Guidelines
Summary of Contents for R134a
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