dT
v
=dT x (RPM
v
/RPM
max
)
dT
v
= the lower temperature rise that can be reached at lower motor speed
RPM
v
= the lower motor speed
RPM
max
= the maximum motor speed that can be reached by the GA VSD
Settings
The compressor should never be running in “lowest dewpoint mode”. (See section Modifying fan motor
settings). The vessel temperature setting has to be set by an Atlas Copco service technician.
Regulation
The element outlet temperature must always be higher than the condensation temperature. (see section
Starting). The software in the Elektronikon regulator of GA90-160+ compressors prevents the outlet
temperature of the compressor element from dropping below the condensation temperature. Electronic valve
(Y152) will be used to switch the Energy Recovery system on or off and to regulate the energy recovery.
Electronic valve (Y151) is used to regulate the oil flow through the heat exchangers and consequently the
compressor element outlet temperature. The regulation will aim for an element outlet temperature of 90 °C /
194 °F.
Start status
Compressor stopped, Energy Recovery 0%, all oil goes through normal oil cooler.
Unloaded operation
No Energy Recovery, oil flows through the regular oil cooler and is PI-regulated.
Loaded operation
• Compressor loads, cooling doesn’t change
• Cooling stabilizes through regular oil cooler with PI-regulation, no Energy Recovery yet
• Electronic valve (Y152) starts opening, the Energy Recovery is started. The flow through the oil cooler
is PI-regulated
• Depending on the needed cooling:
• Less cooling is needed: flow through Energy Recovery cooler is PI-regulated, flow through oil cooler
is minimum
• More cooling is needed: flow through Energy Recovery cooler is maximum, flow through oil cooler
is PI-regulated
Instruction book
2920 1728 05 23
To Next Page
Loading...
