An experiment set for flow and heat transfer characteristics of nanofluids is established and the reliability of this experiment set is verified. Thermo-hydraulic performances of nanofluids flowing through a triangular tube with different structure twisted tapes are experimentally studied. The effects of nanoparticle mass fractions (omega = 0.1 wt%, 0.3 wt% and 0.5 wt%), Reynolds numbers (Re = 400-9000), different structure twisted tapes (P = 25 mm, 40 mm, 55 mm, 65 mm, 75 mm) on the Nusselt number and resistance coefficient enhancement ratios are experimentally investigated. It is found that the triangular tube with twisted tape can improve the Nusselt number by 52.5% and 34.7% at best in laminar and turbulent flow respectively compared with the corresponding smooth tube with the same fluid. The comprehensive performances of nanofluids in the triangular tube with twisted tape are also analyzed based on a comprehensive evaluation index. It is found that large nanoparticle mass fraction and small length of each twisted tape unit are more sensitive to the high comprehensive performance index. In addition, comprehensive performances between the triangular tube with twisted tape and the corrugated tube are compared. It is found that the triangular tube with twisted tape has an advantage over the corrugated tube in laminar flow. (C) 2018 Elsevier Ltd. All rights reserved.