Demand Based Cooling

In commercial machine tools, the cooling medium – oil or water – is tempered centrally by a cooling unit and then stored in an intermediate tank. From there, the cooling medium is fed via a conveyor system to the individual components, such as the electric actuators of the individual axes and the spindle drive. The allocation is purely heuristic, based on different hose cross-sections: small cross-sections for low cooling requirements, large cross-sections for higher cooling requirements. Cooling is therefore constant and not demand-driven. To ensure high machining accuracy, the drives are therefore designed based on the highest expected thermal losses.

Objectives

• An accurate electric drive and cooling unit model enabling the assessment of energy savings potential in the system.
• A suitable demand-based cooling control system for the cooling of electric drives that reduces the energy consumption while maintaining machining accuracy.
• Knowledge of the potentials and limitations of a demand-based cooling system.
• Optimized cooling aggregate (hardware and software).

Benefits

• Knowledge of the actual cooling requirements for individual electric drives
• Thermal models of the drives and cooling system are derived
• Demand-based control strategy to increase energy efficiency of the cooling system is successfully developed

Approach

Based on the thermal model developed, control algorithms for targeted regulation of the flow in the cooling circuits will be developed in the further course of the project. An industrial PC will take over the process-parallel data evaluation and the corresponding control of the valves and feed pump. For demand-oriented cooling, the cooling medium will be specifically allocated to the drives that actually produce waste heat. Drives such as the swivel table will not experience any temperature change during 3-axis machining. This means that the delivery volume must be adjusted accordingly and the cooling line to the respective drives must be opened and closed. The aim is to create a universally parameterisable controller that can be created for one machine tool and then transferred to all machines in this series.

Are you also interested in a cooperation project?

Contact Dominic Fröhlich via email at d.froehlich@ifw.uni.hannover.de or by phone at +49 511 762 4839.