Water Quality Requirements, Parameters - GEA Grasso M-Series Operating Manual

Description of Design and Function
2. Minimum suction overheating in compressor
inlet: "wet" operation is not possible.
3. For Δ p = p - p
≤ 2.9 bar an external oil pump to
o
be taken for compressor sizes H to N.
4. For π ≥ 8 gas vibration protection is required.
5. For CO usage the use of a completely electri-
2
fied oil pump for injection and function oil needs
to be checked in all types of compressors
depending on the operating conditions;
6. The discharge temperature t
above the condensing temperature (t
K).
7. Due to the solubility of refrigerant in the oil fol-
lowing applies:
•
for Ammonia:
t ≥ t + 5 K;
e oil
t ≥ t + 10 K,when using a PAG oil (solubil-
e oil
ity of the refrigerant in the oil).
•
For R22, R134a, R404A, R407C, R410A,
R507, CO2, natural gas, carbohydrate mole-
cules:
t ≥ t + 10 K, wherein solubility of the
e oil
refrigerant in the oil.
• To determine the permitted difference
between the discharge temperature (t
and oil intake temperature (t
viscosity and the solubility diagram for
the refrigerant-oil pair from the lubrica-
tion supplier need to be adhered to.
8. Ensure that the oil viscosity will be ≥7...70 cSt (=
-6
10 m²/s) for the oil supply to bearings. Take
into account the drop in viscosity due to refriger-
ant dissolved in the oil!
9. Limits for temperature differences will be consid-
ered in compressor selection programs.
10. The oil temperature at the compressor inlet must
be at least 18°C, the oil must be preheated if
necessary.
11. The rate of temperature change at compressor
suction side should not exceed 0,1 K/s.
12. Rotation direction: view of compressor's driving
shaft clockwise.
13. For individual cases outside the permitted speed
coordination needs to made with the manufac-
turer.
50
must be 10 K
e
≥ t + 10
e c
)
e
) the set
oil
GEA Refrigeration Germany GmbH | P_261511_1 | Generated 01.04.2015
Operating Manual | GEA Grasso M-Series
p
Maximum permitted pressure
p
Suction pressure
0
Δp
Pressure difference
π
Pressure ratio
t
Suction temperature (compressor inlet)
0h
t
Discharge temperature (compressor outlet)
e
Condensing temperature
t
c
oil inlet temperature into the compressor
t
oil
Notes:
1. During tests of a certain application case, all the
conditions specified in the table must be consid-
ered and adhered to.
2. Should the given limits not be adhered to in indi-
vidual cases, then the manufacturer needs to be
contacted.
3. In addition to the application limits stated in the
tables, the applicable operating conditions of the
compressor type in question must also be con-
sidered (e. g. start-up regime, oil pressure, oil
quantity etc.).
4. Depending on the refrigeration requirements,
economiser operation takes place at a control
slide position between 100% and approx. 70%
control slide position.
5. When using R134a as a refrigerant and a evap-
orating temperature > 60 °C consultation with
the manufacturer must be made.
7.12.5 Water quality requirements,
parameters
All water bearing components from the manufacturer
deliver an optimum performance and provide maxi-
mum protection from corrosion, provided you meet
all of the limiting values recommended in VDI 3803
issue 2010-02 (Tab. B3) for non-corrosive water and
adequate water conditioning.
Screw Compressor Packages