Atlas Copco GA 110 VSD+ Instruction Book page 27

Instruction book
• Water outlet temperature: 55.9 °C / 132.6 °F
The formula to calculate the amount of recovered energy results in (2):
• 4.2 x 4 x (55.9-47.5) = 141 kW ( ± as indicated on the curve of 85 °C)
The outlet temperatures for a water flow of 4 l/s can be calculated backwards from formula (2):
• Toutlet = 47.5 + (141 / (4.2 x 4)) = 55.9 °C (132.6 °F)
Total pressure drop on waterside is (1):
• pd = (4.23 x 4²) + (1.62 x 4) = 74 kPa = 0.74 bar (10.73 psi)
Example point Z
• Compressor unit: GA 160 VSD+ -50 Hz
• Working pressure: 8 bar / 116 psi
• Water flow: 1 l/s / 2.12 cfm
• Water inlet temperature: 55 °C / 131 °F
• Water outlet temperature: 82.0 °C / 179.6 °F
The formula to calculate the amount of recovered energy results in (2):
• 4.2 x 1 x (82-55) = 113.4 kW
The outlet temperatures for a water flow of 1 l/s can be calculated backwards from formula (2):
• Toutlet = 55 + (113.4 / (4.2 x 1)) = 82 °C (179.6 °F)
Total pressure drop on waterside is (1):
• pd = (4.23 x 1²) + (1.62 x 1) = 5.85 kPa = 58.5 mbar (0.85 psi)
This proves that it is possible to work at higher temperatures, but with less heating power.
The temperature of the vessel can be set to 100 °C (212 °F) as well. The installation can
work in a higher curve, to obtain a higher water outlet temperature. This setting must be
done by a service technician of Atlas Copco.
• Compressor unit: GA 160 VSD+
• Working pressure: 8 bar / 116 psi
• Water inlet temperature: 30 °C / 86 °F
• Water outlet temperature: 60 °C / 140 °F
The lowest curve is the maximum energy that can be recovered. If it is necessary to work in the
area below the lowest curve, you have to calculate with the 140.5 kW anyway.
dT = 30 °C/ 54 °F (60 °C - 30 °C / 140 °F - 86 °F)
c = 4.2 J/kgK (for water)
Q = 140.5 kW (lowest curve)
Formula for recovered energy is : ==> Q = m x c x dT
==> m = Q / (c x dT)
==> m = 140.5 / (4.2 x 30)
==> m = 1.115 l/s
Additional safety precautions
• The parts must only be lifted using suitable equipment in accordance with the applicable
safety regulations. Loose or pivoting parts must be securely fastened before lifting.
9829 3178 63
25