The thermal performance, embodied energy, and environmental CO₂ emissions are evaluated experimentally for MWCNT/water nanofluid flow in a double pipe U-bend heat exchanger. The experiments were conducted at different Reynolds number (3500–12000) and particle volume concentrations (0.05%–0.3%). The thermal conductivity and viscosity are augmented by 15.27% and 9.15% at a temperature of 70 °C with respect to water data. The Nusselt number, heat transfer coefficient, thermal performance factor are enhanced by 31.3%, 44.17%, and 25.5% at a particle concentration of 0.3% and a Reynolds number of 10,005 over water data. The pressure drop, pumping power, friction factor penalty are 17.05%, 15.96%, and 14.29%, at 0.3% particle concentration and a Reynolds number of 10,005, compared to water. The effectiveness and number of transfer units are increased by 2.49% and 2.75% at 0.3% particle concentration and a Reynolds number of 10,005 compared to water data. The cost, weight, embodied energy, and CO₂ emissions are analyzed based on the enhanced effectiveness of the heat exchanger. The total embodied energy from the heat exchanger using water is 403.7 MJ and it reduced to 393.1 MJ with 0.3% nanoparticle concentration. The heat exchanger cost is reduced to 61.46$ using 0.3 vol % of nanofluid whereas it is 63$ using water. The environmental CO₂ emissions released from the heat exchanger are reduced to 81 kg of CO₂ using 0.3 vol % of nanofluid, whereas it is 83.3 kg of CO₂ using water.

热性能、隐含能量和环境 CO ₂在双管 U 形弯管换热器中，对 MWCNT/水纳米流体流动的排放进行了实验评估。实验在不同的雷诺数 (3500–12000) 和颗粒体积浓度 (0.05%–0.3%) 下进行。相对于水数据，在 70 °C 的温度下，热导率和粘度分别增加了 15.27% 和 9.15%。在粒子浓度为 0.3% 和雷诺数为 10,005 的水数据下，努塞尔数、传热系数、热性能因子分别提高了 31.3%、44.17% 和 25.5%。与水相比，在 0.3% 的颗粒浓度和 10,005 的雷诺数下，压降、泵送功率、摩擦系数损失分别为 17.05%、15.96% 和 14.29%。转移单位的效率和数量在0时分别增加了2.49%和2.75%。与水数据相比，3% 的颗粒浓度和 10,005 的雷诺数。成本、重量、隐含能量和 CO₂排放分析基于热交换器的增强效率。使用水的热交换器的总隐含能量为 403.7 MJ，当纳米颗粒浓度为 0.3% 时，它减少到 393.1 MJ。使用 0.3 vol% 的纳米流体，热交换器成本降低到 61.46 美元，而使用水则为 63 美元。使用 0.3 vol% 纳米流体，热交换器释放的环境 CO ₂排放量减少到 81 kg CO ₂，而使用水则为 83.3 kg CO ₂。