Coupled experimental and numerical study of innovative nanofluids: from characterization to their performances in a prototype of heat exchanger

Sigma Energy Storage(SES)Inc.最近开发了一种用于存储来自网络或可再生能源的过剩电能问题的原型。这种能量以两种形式储存：压缩空气和热能。第二种形式包括由两个同心管组成的热交换器，一侧有压缩空气，以及SES专门为此应用开发的微流体。该项目涉及对该换热器和微/纳米流体的优化，以便在能量存储和回收阶段更好地传递热能。微流体的主要缺点是容易结块和沉淀，从而失去任何兴趣并导致更大的泵消耗。这也可能发生在纳米流体很差或没有功能化的情况下。该项目分为4个行动，从纳米粒子的合成，到纳米流体的热物理性质的制备和表征，到在大学开发的精密仪器换热器中对这些纳米流体进行动态研究，并通过直接的数值模拟进行优化。通过控制整个链，目标是确定在热容和导热方面最有效的纳米流体，以及最稳定的纳米流体，即其性质在大量循环(原型为24000个循环)后保持不变。这种混合的500千瓦存储单元应该能够以非常低的每千瓦时0.05加元的非常低的成本恢复大约20小时的能量，并通过实例证明非常适合偏远地区(北部)或危险地区(战争)。

Sigma Energy Storage (SES) Inc. has recently developed a prototype for the storage of electrical energy issue of overproduction from the network or from renewable sources. This energy is stored in two forms: compressed air and thermal energy. This second form involves a heat exchanger formed by two concentric tubes with compressed air on one side and a microfluid developed specifically for this application by SES. This project concerns the optimization of this exchanger and of the micro-/ nanofluid for a better transfer of thermal energy during the phases of storage and return of energy. The main disadvantage of microfluid is their propensity to clump and settle, thus losing any interest and resulting in greater consumption of the pump. This may also occur for nanofluids poorly or not functionalized. The project is divided into 4 actions ranging from the synthesis of nanoparticles, to the preparation and characterization of the thermophysical properties of nanofluids, to the dynamic study of these nanofluids in a finely instrumented heat exchanger developed at the University and its optimization by direct numerical simulations. By controlling the whole chain, the objective is to identify the nanofluid being both the most efficient in terms of heat capacity and thermal conductivity and the most stable, i.e. whose properties remain constant after a large number of cycles (24000 cycles for the prototype). This mixed 500 kW storage unit should make it possible to restore energy for about 20 hours at very low cost 0.05 CAD per kWh per cycle and turns out perfectly suited for remote areas (Northern) or dangerous areas (war) by examples.******