Internal Combustion Engine (ICE) cooling system is receiving a new technological interest for the influence it has on primary harmful and CO2 emissions reduction. Improvements on pump efficiency are requested to reduce its required energy during real on-the-road operation. Present technology always considers centrifugal pumps whose efficiency is highly dependent on rotational speed: consequently, pumps designed to have a very high efficiency at design point, show poor performances during usual operation, wasting energy.

This study aims to assess the screws pumps potentiality to substitute the traditional centrifugal pumps for engine cooling. The main advantage is that positive displacement pumps have an efficiency ideally non-dependent on rotational speed, flow rate and head delivered, so having requirements that can fit more the engine cooling features.

A novel comprehensive zero-dimensional mathematical model has been formulated to predict the performances of triple-screw pumps, in terms of volumetric, indicated and mechanical efficiency as a function of main operating conditions of the pump. A wide experimental activity has been done, resulting in a good agreement with predictions in spite of the manufacture of the pump, which privileges a low-cost solution as it is requested for the specific sectors of application. The model, once experimentally validated, demonstrates a high validity as virtual platform for a model-based design, thus offering the possibility to include design aspects particularly suitable for engine cooling systems. At last, by simulating the World Harmonized Transient Cycle on an F1C IVECO 3l engine, the triple-screw pump shows an average efficiency about 8% greater than that of the centrifugal pump, leading to an energy saving equal to 18.5%. This result leads the way to the use of screws pumps also in the engine cooling system of an on-the-road vehicle, which could represent a new potential application, never considered before.

内燃机 (ICE) 冷却系统因其对主要有害物质和二氧化碳排放减少的影响而受到新技术的关注。要求提高泵的效率，以减少实际行驶过程中所需的能量。目前的技术总是考虑离心泵，其效率高度依赖于转速：因此，在设计点上设计的泵具有非常高的效率，在正常运行中表现出较差的性能，浪费能源。

本研究旨在评估螺杆泵替代传统离心泵用于发动机冷却的潜力。主要优点是正排量泵的效率理想情况下不依赖于转速、流量和输送的扬程，因此具有可以满足更多发动机冷却功能的要求。

一种新颖的综合零维数学模型已被制定来预测三螺杆泵的性能，在容积效率、指示效率和机械效率方面，作为泵的主要运行条件的函数。尽管制造了泵，但已经进行了广泛的实验活动，结果与预测非常吻合，这使得低成本解决方案成为可能，因为它适用于特定的应用领域。该模型经过实验验证后，证明作为基于模型的设计的虚拟平台具有很高的有效性，从而提供了包括特别适用于发动机冷却系统的设计方面的可能性。最后，通过在 F1C 依维柯 3l 发动机上模拟世界协调瞬态循环，三螺杆泵的平均效率比离心泵高8%左右，节能18.5%。这一结果为在道路车辆的发动机冷却系统中也使用螺杆泵开辟了道路，这可能代表一种新的潜在应用，以前从未考虑过。