Comparison on the energy absorbed of volumetric and centrifugal pumps for automotive engine cooling

Abstract Engine thermal management can reduce significantly CO 2 emissions in road vehicles without altering sensibly the engine layout. However, more efficient auxiliaries also participate to fuel consumption saving and, therefore, reduction. Typically, centrifugal cooling pumps are adopted as circulating devices, but their efficiency varies highly with rotational speed, wasting energy during real operation despite being optimized at design point. Instead, volumetric keep a high far from it, enhancing overall efficiency. In this paper, performances of screw-type pump have been compared those considering same circuit mid-size for passenger vehicles. Both designed satisfy flow rate required by homologation cycle, while verifying capability cool operating maximum power. Once prototyped, performance maps measured, showing Best Efficiency Point both cases. screw has better off-design conditions, strictly dependent on its speed which changes driving. The comparison two done reproducing WLTC dynamic test bench. adjusted deliver produced requested engine. Results show that prototyped absorbs 21% less than pump, reducing 0.28 g/km.