Experimental Research on the Corrosion and Heat Transfer Characteristics of HCl-H2O Vapors Outside a 3-D Finned Tube

Abstract

Hydrochloric acid (HCl) corrosion in the overhead condensation system of crude distillation units is a common occurrence in refinery worldwide. The HCl corrosion can not only reduce the heat transfer performance of the heat exchanger, but also lead to the thinning of the heat exchanger wall, and even cause perforation and leakage. Therefore, it is necessary to study the corrosion and heat transfer characteristics of the heat exchanger under this condition, in order to improve the heat transfer performance and safety. In this paper, a 3-D finned tube with high heat exchange efficiency was used to study the corrosion and heat transfer characteristics with the moist air containing HCl outside it. The effects of different H2O volume fraction and HCl volume fraction on the HCl dew point of the 3D finned tube were studied. The corresponding HCl dew point prediction formula was fitted by the experimental data. In addition, the heat transfer characteristics of 3-D finned tube with HCl-H2O vapors outside was studied. The experimental results showed that the HCl dew point increased with an increase of the H2O volume fraction and HCl volume fraction. Furthermore, for the 3-D finned tube, the heat transfer coefficient increased with an increase of the H2O volume fraction and HCl volume fraction. In addition, when the H2O volume fraction was 10%, the 3-D finned tube had 87.2%–95.4% higher heat transfer coefficient and 91.3%–97.1% higher heat transfer rate compared with the smooth tube.