Tube & Fin Oil Cooler for Loaders

Tube & Fin Oil Coolers for Loaders

The operating environment (e.g. mine, construction site) and working mode (frequent loading and unloading, lifting, steering) of loaders determine the extremely harsh heat dissipation requirements of their hydraulic systems and gearboxes:

High thermal load: the hydraulic system working pressure reaches 20-35MPa, and the oil temperature is easy to rise to 80-90℃; the oil temperature of the gearbox can reach 110℃ or more under heavy-duty working conditions. High heat load: hydraulic system working pressure reaches 20-35MPa, oil temperature easily rises to 80-90℃; oil temperature of gearbox under heavy load condition can reach over 110℃.

Strong vibration: engine vibration (frequency 10-50Hz), working device impact (such as bucket inserted into the material) and driving bumps, easy to cause fatigue cracking of the cooler welding joints.

High dust pollution: the concentration of dust in the air during mining operation can reach 100-500mg/m³, which is easy to be blocked between the fins and reduces the heat dissipation efficiency.

Space limitation: the engine compartment is compact (especially for small loaders), the cooler needs to realize efficient heat dissipation in the limited space.

Selection of key parameters

Calculation of heat dissipation power:

Formula: Q = c-ρ-V-ΔT

Q: Heat dissipation power (kW)

c: Specific heat capacity of oil (hydraulic oil is about 1.9kJ/(kg・℃))

ρ: Density of oil (about 850kg/m³)

V: Flow rate of oil (m³/s)

ΔT: Difference between inlet and outlet temperature of oil (℃)

Example: The flow rate of hydraulic oil of a certain loader is 200L/min, the inlet oil is 85℃, and the outlet oil is 65℃, then Q = 1.5L/min, then Q = 1.0L/min, then Q = 1.0L/min. Example: a loader hydraulic oil flow 200L / min, inlet oil 85 ℃, out of 65 ℃, then Q = 1.9 × 850 × (200/60/1000) × (85-65) ≈ 10.7kW (the actual selection needs to be enlarged by 1.2-1.5 times, that is, 13-16kW).

Matching of fin parameters:

Dusty environment: choose louvered fins with 3-5mm spacing;

Clean environment: choose corrugated fins with 2-3mm spacing to improve efficiency.