In this paper, a double-pipe heat exchanger with a series of corrugated tubes as inner tubes is studied for the adequate cooling of thermal-hydrolyzed sludge. A numerical model, built on the Spalart-Allmaras model, is validated to have the ability for characterizing the flow and heat transfer performance of sludge. The influencing factors, including the flow parameters of the sludge and cooling water, and the geometric configurations of the corrugated tube are parametrically investigated. The ratio of Nusselt number (Nu/Nu₀), the coefficient of flow resistance (f/f₀) of the sludge, the synthesis factor of performance (η) and the ratio of the heat transfer increase over the pump power increase ($\zeta$) are used as the performance assessment indexes. The results show that increasing Re_sludge can negatively affect η and η tends to be stable when Re_water is higher than 1.2 × 10⁴. Decreasing S/D and increasing H/D result in a higher ratio of flow resistance f/f₀ and a higher ratio of Nu/Nu₀. The corrugation height (H) shows a larger effect than the corrugation length (S). In practical applications, the optimal flow rates of the sludge for the studied corrugated tubes are recommended to be within the range of 1.2–1.5 m/s.

在本文中，研究了以一系列波纹管作为内管的双管换热器，以充分冷却热水解污泥。建立在 Spalart-Allmaras 模型上的数值模型经过验证，能够表征污泥的流动和传热性能。对影响因素，包括污泥和冷却水的流动参数以及波纹管的几何形状进行了参数化研究。努塞尔数比（Nu/Nu ₀）、污泥流动阻力系数（f/f ₀）、综合性能系数（η）和传热比随泵功率增加而增加（$\zeta$)作为绩效考核指标。结果表明，增加Re_污泥会对η产生负面影响，当Re_水高于 1.2 × 10 ⁴时，η趋于稳定。降低S/D和增加H/D导致更高的流动阻力比f/f ₀和更高的Nu/Nu ₀比。波纹高度 ( H ) 显示出比波纹长度 ( S ) 更大的影响）。在实际应用中，建议研究波纹管的最佳污泥流速在1.2-1.5 m / s范围内。