Selection Using The Bitzer Software - Bitzer KT-600-3 Handbuch

• air (additional fan)
• and / or electronically controlled refrigerant injection (RI)
• or water (water-cooled cylinder heads for compressors 4JE .. 4FE, 6JE .. 6FE).
When a compressor is shut off, its additional cooling must also be shut off in each case. With a fan, this is done by
simply coupling the compressor and fan contactor. A solenoid valve that shuts off the water flow when the com-
pressor is at standstill must be connected upstream of the water-cooled cylinder head. Continuously switched-on
additional cooling increases the risk of refrigerant condensation in the cylinder head and reduces the effect of the
oil heater. This can lead to a high concentration of refrigerant in the oil.

3.1 Selection using the BITZER Software

The BITZER Software can be used to design compound systems for semi-hermetic/open drive and 2-stage recip-
rocating compressors. The procedure is illustrated here by way of example:
Refrigerant
Refrigerating capacity
3 compressors
Operating conditions
Conditions in power
supply
Capacity control
Tab. 1: General conditions for a calculation example in the BITZER Software. Evaporators are each equipped with an internal heat exchanger.
KT-600-3 // PDF Download
R134a
100 kW
t = -10°C
o
t = 45°C
c
Δt = 20 K
oh
400 V / 3 / 50 Hz
Compressor 1 with frequency in-
verter and 50% power, compressors
2 and 3 each with 25%.
27