I. Calculation of heating value: (rough calculation)
Based on processing heat, heat generated by pump power consumption, heat absorbed by oil tank and pipeline, total heating power can be calculated as:
P(Heat): Total heating value of working equipments (KW)
P1: Processing heat of working equipments (friction between cutter and work piece) (KW)
Processing heat can be attributed to power loss of spindle driving motor, amounting to 30%~40% (heavy stock-removing machines) of spindle driving motor power.
P2: Heat (kW) generated by consumption power of various circulating pumps (including liquid pump, reflux pump, circulation for chip removal and filtration) shall be calculated as 50% of overall pump power.
P3: Heat (kW) generated by cutting fluid (oil) tank and pipeline
When the temperature of cutting fluid (oil) tank is lower than ambient temperature, heat will be transferred from the surface of cutting fluid (oil) tank and pipeline to high-temp air. The transferred heat can be calculated as:
K: Heat transfer coefficient of cutting fluid tank to air (W/m2·℃)
In general K=11.6～23.2
A: Heat transfer area and effective fluid tank surface area (m2)
ΔT: Temperature between ambient and fluid temperature (℃)
II. Example of model selection:
Spindle power of a stock-removing machine is 10kW; total pump power is P2=2.2+2.2+3.7=8.1KW; the surface area of oil tank is 4M²; fluid heat transfer coefficient is 20 W/M²·℃; room temperature is 35 ℃; fluid temperature is 25℃. Under such conditions, the overall heating value of cutting fluid can be calculated as:
∴ P (Heat) =P1+ P2 + P3=4+4.1+0.8=8.9 KW
As a result, you can select MCS-100S precision immersion chiller, with a cooling capacity of 10KW.